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date: 17 November 2019

The Constitution of the United States and Foreign Relations

Summary and Keywords

Foreign relations under the US Constitution starts with the paradox, also seen in domestic matters, of relatively scant text providing guidance for the exercise of vast power. Founding understandings, structural inference, and ongoing constitutional custom and precedent have filled in much, though hardly all, of the framework over the course of two hundred years. As a result, two basic questions frame the relationship between the Constitution and US foreign policy: (1) which parts of the US government, alone or in combination, properly exercise authority in the making of foreign policy; and (2) once made, what is the status of the nation’s international legal obligations in the US domestic legal system.

The making of American foreign policy is framed by the Constitution’s commitment to separation of powers. Congress, the president, and the courts are all allocated discrete yet significant foreign affairs authority. Determining the exact borders and overlaps in areas such as the use of military force, emergency measures, and treaty termination continues to generate controversy. The status of international law in the US legal system in the first instance turns on whether resulting obligations derive from agreements or custom. The United States enters into international agreements in three ways: treaties, congressional-executive agreements, and sole executive agreements. Complex doctrine deals with the domestic applicability of treaties in particular. US courts primarily apply customary international law in two basic ways. They can exercise a version of their common lawmaking authority to fashion rules of decision based on international custom. They also apply customary international law when incorporated into domestic law by statute.

Keywords: Charming Betsy, congressional-executive agreement, Curtiss-Wright, customary international law, law of nations, non-self-executing, self-executing, sole executive agreement, treaty, Youngstown

“Invitation to Struggle”

One may say of the Constitution’s role in making foreign policy that, to paraphrase Gertrude Stein, there’s no there there. The most prominent scholars in the field ritually point out how sparse, partial, and even silent the document is when it comes to matters that relate to the external relations of the United States with other states and international law. Harold Hongju Koh writes, “One cannot read the Constitution without being struck by its astonishing brevity regarding the allocation of foreign affairs authority among the branches.”1 Toward the close of the 20th century, Louis Henkin wrote, “Where . . . is the power to recognize other states or governments; to maintain or rupture diplomatic relations; to open consulates in other countries and permit foreign governments to establish consulates in the United States; to acquire or cede territory; to grant or withhold foreign aid; to proclaim a Monroe Doctrine, an Open-Door Policy, or a Reagan Doctrine; indeed to determine all the attitudes and carry out all the details in the myriads of relationships with other nations that are ‘the foreign policy’ and ‘the foreign relations’ of the United States? . . . These ‘missing’ powers, and a host of others, were clearly intended for, and have always been exercised by, the federal government, but where does the Constitution say that it shall be so?”2 Perhaps the most trenchant observation came near the turn of the 20th century from Edward S. Corwin, who observed that, “the Constitution is an invitation to struggle for the privilege of directing American foreign policy.”3

The Constitution’s sparse treatment of foreign affairs is exaggerated, yet this commentary has a point. Constitutional text in general fails to address critical matters considered mainly domestic as well, including “state sovereign immunity,” the right to privacy, executive privilege, and removal of federal officers. Yet it remains true that the document remains at its most Delphic in foreign affairs. For this reason, jurists and commenters often try to supplement the text with the “original understanding” of the constitutional founders. As Justice Robert Jackson noted in Youngstown Sheet and Tube Co. v. Sawyer, itself a major foreign affairs landmark, “Just what our forefathers did envision, or would have envisioned had they foreseen modern circumstances, must be divined from materials almost as enigmatic as the dreams Joseph was called upon to interpret for Pharaoh.”4 In consequence, perhaps the most important source for determining the Constitution’s application in foreign affairs is “custom” (alternatively referred to as “historical gloss”)—how the three branches of government, including Supreme Court precedents, have worked out the Constitution’s meaning over two hundred years. Justice Felix Frankfurter, also writing in Youngstown, perhaps put it best in saying, “Deeply embedded traditional ways of conducting government . . . give meaning to the words of text or supply them. . . . It is an inadmissibly narrow conception of American constitutional law to confine it to the Constitution and to disregard the gloss which life has written upon them.”5

Conceptually, the Constitution’s application to foreign affairs breaks down into two broad categories. The first addresses how the United States engages in foreign policy, including acceptance of international legal obligations. This question is determined by the Constitution’s bedrock commitment to separation of powers. Accordingly, the legislative, executive, and judicial branches, alone or in combination, each enjoy discrete powers in determining the nation’s external relations. Second, constitutional law necessarily addresses whether and to what extent the international legal obligations that the United States has undertaken have effect in the nation’s domestic legal system. This question in turn depends on whether the international obligation at issue derives from an international agreement or customary international law. As complex as this breakdown may be, specific doctrines can be more complex still. The Constitution’s application to foreign affairs has grown only more complex, moreover, in light of the federal government’s response to the attacks of 9/11 and to globalization generally.

The Founding

The American ongoing predilection to fix the Constitution’s meaning as it was “originally understood” when promulgated requires a consideration of the founding. Considering the founding in turn begins with understanding the American experience of government prior to independence. Americans living under the British Empire had ample experience with constitutional frameworks, but correspondingly little with foreign relations. Under what has later been called “the Constitution of Empire,” the British government held a virtual monopoly on dealings with other nations, with the Crown in particular holding the prerogative powers to make war, undertake treaties, and receive ambassadors. Even within the Empire, Americans were generally left to focus on local matters. Under a system that amounted to “imperial federalism,” the Parliament at Westminster enjoyed a recognized authority to regulate commerce within the Empire, but generally left matters within the colonies to their own assemblies as overseen by royal governors. It was Parliament’s attempts to enact taxes and legislation directly on the colonies during the 1760s that led to American resistance, in part on the ground that such assertions violated settled constitutional arrangements.6

With independence, Americans faced the challenge of national self-governance. Broadly speaking, this task ran into two existential sets of problems, foreign and domestic. Most obviously, American representatives had to formally engage in foreign affairs for the first time. During the revolution, the challenge largely meant securing alliances and loans from friendly governments. This effort led to several major triumphs, not least the 1778 Treaty of Alliance with France, secured in no small part through the efforts of US envoy Benjamin Franklin, and without which the revolution may not have succeeded. Yet potentially greater problems paradoxically arose in the years after the war ended, a time John Quincy Adams termed, the “critical period.”7 It soon became clear that the new national government under the Articles of Confederation was far too weak to conduct external relations in a world of aggressive superpowers. Not only did that framework lack an executive or judiciary but also Congress itself lacked the authority to directly tax, legislate, or regulate interstate and foreign commerce; instead it could request the state legislatures to do so to implement national policy. These weaknesses led to several foreign policy threats. The new nation could not effectively retaliate against trade wars, as when the United Kingdom cut off the access to imperial trade that American shipping had previously enjoyed. Congress likewise could not effectively engage in real wars as it had to rely on the states to raise an army and provide for a navy. War, moreover, loomed as a real possibility as Congress also lacked the power to enforce US treaty obligations in the face of state recalcitrance, a failure that threatened renewed conflict with the United Kingdom in particular.8

Matters looked no better on the domestic side. As the national government was weak, governance mainly fell to the several states. Most of the first state constitutions concentrated power in the legislatures. These typically selected and controlled weak governors. They also selected and influenced state judiciaries. A basic assumption underlying these frameworks was that representative assemblies would be guardians of liberty. Much to the shock of many in the founding generation, the new state legislatures instead fell prey to faction and demagogues, enacting laws that undermined right of property, contract, and trial by jury. John Adams termed the discovery as “democratic despotism,” more often known in the 21st century as majoritarian tyranny.9 Both the diagnosis and solution principally came in the form of separation of powers. As James Madison observed, the problem with most state constitutions was that they concentrated legislative, executive, and judicial power in the same set of hands—the “impetuous vortex” of the legislatures.10 A solution to majoritarian tyranny in any new frame of government would mean a stronger executive and independent judiciary to achieve a balance among the three branches of government.

Madison took the lead in advocating a new framework that would address the crises in foreign affairs with a genuinely powerful national government and confront the domestic problem of majoritarian tyranny with structural checks featuring separation of powers, augmented by retaining a division of powers between the national and state governments. The foreign and domestic solutions are often seen as discrete. But, in fact, they are intertwined. For all that it addressed domestic problems, separation of powers came to the fore as a mechanism to prevent the concentration and abuse of power. The new federal government that emerged from the Federal Convention in Philadelphia accordingly reflected separation of powers in foreign affairs no less than in domestic matters.11

The text of the Constitution demonstrates the commitment to a federal government capable of conducting foreign affairs yet nonetheless structured to prevent a tyrannical concentration of power in precisely that realm. Among other things, Congress enjoys the power to regulate commerce among the states and with foreign nations, to raise an army and provide for a navy, to define and punish offenses against the law of nations, and—notably in a document that otherwise shifted power to the other branches—to declare war.12 The president’s specific foreign affairs powers include, among others, authority as commander in chief of the armed forces, to make treaties (with the advice and consent of two-thirds of the senators present), to appoint ambassadors (subject to majority approval by the Senate), and to receive ambassadors (understood as a power to recognize foreign governments).13 Often overlooked, the Supreme Court would serve as a court of first instance in any case involving diplomats, and the anticipated federal judiciary in general would have the power to apply the then critically important body of international law known as admiralty as well as any prior or future treaties made by the United States, which, along with federal statutes and the Constitution itself, were designated as the supreme law of the land.14 Part and parcel of the shift to a strong national government was the further, near total, marginalization of the states in the conduct of foreign affairs. Among the few exceptions, the Constitution did permit a state to enter into a “compact” with a foreign government, but even then only with the approval of Congress.

This sketch, like the Constitution itself, sets forth the framework for US foreign relations but hardly resolves it. That task would fall not just to the text, but also to the interpretations of the foregoing history, inferences from structure, and constitutional custom, including judicial precedents. The result no less would be influenced by US foreign policy and international affairs. Of particular importance in this regard is the nation’s rise from weak republic, to regional force, to world power, superpower, and, for a time, hegemon. These developments would put tremendous pressure on the founding structure, generally in favor of the president, with results that continue to generate debate, controversy, and precedents.

Separation of Powers and Foreign Affairs

Powers of Congress

Constitutional analysis begins with considering the grant of authority to the given government actor. As noted, the Constitution’s text accords a number of foreign affairs powers to Congress, yet also leaves out many others. As also noted, omissions also exist with regard to domestic powers. Nonetheless, for a time courts and commentators used the ostensibly greater gaps with regard to foreign affairs as a basis to develop distinct sources for various exercises of congressional authority in external relations. In more extreme forms, this approach dictated that federal exercise of domestic powers were to be subject to close review of their basis in constitutional text, structure, or history, while federal authority in foreign relations would be assumed to exist simply as a function of US nationhood. This resulting “foreign affairs exceptionalism” reached its height in the 19th century as Congress grappled with new problems and novel assertions. Probably the principal source of federal authority that this approach cited was sovereignty. In the notorious Chinese Exclusion Case, the Supreme Court upheld an Act of Congress that barred Chinese immigration. In a follow-up, it likewise let stand a federal statute authorizing the deportation of Chinese laborers who could not prove they had entered the country prior to the initial prohibition. A threshold problem with these measures was that the Constitution lacked any grant of congressional authority over immigration. Undaunted, the court held that both the powers to deport and exclude were necessary powers for sovereign nation-states and so did not require a textual grant of authority. Dissenting opinions cited the concern that such an inchoate basis of authority represented a dangerous challenge to the idea that the Congress and the federal government enjoyed broad but ultimately limited, enumerated powers.15

For the most part, that idea has prevailed. Congress has taken advantage of the grants of authority that the text does make. From the first, it has passed laws that define and punish offenses against the law of nations (the 18th-century term for international law), that establish and regulate the military, that incorporate provisions of treaties through the necessary and proper clause, and that regulate commerce with foreign nations. Through the mid-20th century Congress also exercised its power to declare war, at least in major conflicts. By contrast, presidents have undertaken numerous lesser conflicts without a formal declaration of war—sometimes with and sometimes without other forms of congressional authorization—throughout the nation’s history, from armed conflict with the Barbary States in 1801 through intervention against Libya in 2011. Even with regard to larger conflicts, Congress increasingly bowed to presidential assertions after the advent of World War II and the Cold War. In particular, it failed to declare war in Korea or any other major or minor conflict since. Congress has, however, authorized subsequent major conflicts without a formal declaration, including Vietnam, the two Gulf Wars, and the war in Afghanistan. The problem in this regard is that authorizations are easier to obtain than actual declarations of war. After the Vietnam War, Congress attempted to reassert its authority through the War Powers Resolution (WPR), a statute that in effect requires the president to seek congressional approval for significant military deployments after ninety days.16 Given Congress’s readiness to authorize conflicts, the efficacy of the WPR remains an open question. Beyond armed conflicts, where textual gaps exist, Congress has relied on various approaches, common to constitutional analysis in general, to fill them. One is to base a power on original understanding. Another is to rely on custom. Most common is simply a broad reading of the grants that do exist. Typical here is reliance on the foreign commerce clause, which courts have read more broadly than their interstate counterpart. Even more broadly, the Supreme Court has since based Congress’s authority to regulate immigration as a corollary of the express power to naturalize citizens, rather than on vague notions of sovereignty.

Powers of the President

Deriving the foreign affairs powers of the president presents similar challenges, but in sufficiently exaggerated form to be different in kind. On one hand, constitutional text provides even fewer specific grants of foreign affairs powers to the executive branch. On the other hand, presidents have taken advantage of external crises and congressional inertia to assert authority nowhere in the Constitution’s text. One result is radically different conceptions of the basis for presidential authority. Another is a setting in which conflict between Congress and the president is all but perpetually assured.

As with Congress, presidential assertions of foreign affairs authority have generated little controversy when they remain squarely within the Constitution’s express grants. Presidents from the first have executed laws dealing with external affairs, such as trade. They have jealously guarded the authority to command the armed forces, within and sometimes beyond the bounds of Congress’s authority to regulate the military. They have made treaties in conjunction with two-thirds Senate approval. They have routinely appointed ambassadors and other diplomats, subject to Senate majority approval. As the Supreme Court reaffirmed, they have also traditionally exercised the power to recognize the government of a given state under the authority to receive ambassadors. Scholars have also argued that presidents at least through the first decades of the republic considered themselves under a duty to take care that the nation’s international treaty and customary international law obligations be executed along with domestic measures.

Controversy arises when presidents have claimed the many foreign affairs powers not specified in the Constitution. Sometimes, especially early in the nation’s history, they have done so modestly, relying on various other sources of constitutional interpretation. With the rise of the United States as a world power, the executive more and more has claimed power not specifically granted more boldly. Among the earliest controversial assertions was President Washington’s proclamation of American neutrality in the war between revolutionary France and Great Britain.17 The federal judiciary never had the opportunity to pass upon this action. It did, however, later affirm that the president had an executive power to have the armed forces bombard a nation with whom the United States was at peace in order to protect American property and citizens abroad.18 Similarly, the Supreme Court in the Prize Cases also affirmed President Lincoln’s order of a naval blockade on the so-called Confederate states, though this action had some basis in acts of Congress authorizing a military response to invasion or insurrection.19 Conversely, President Truman committed US forces to a full-blown war in Korea without either a declaration of war or statutory authorization.20 President Carter, confirming a drift from earlier tradition, claimed the authority to terminate a treaty with Taiwan, a power unmentioned in the Constitution, and an issue to date dodged by the Supreme Court.21 Not surprisingly, the trend toward broad assertions of executive foreign affairs authority accelerated after the attacks of 9/11. Among other things, President George W. Bush’s administration asserted the power to detain terrorism suspects and create military commissions in which to try them, assertions the court did not directly address even as it rejected rules against the executive on other grounds.22

Presidential claims of foreign affairs powers of this sort have generally been justified and contested in two general ways. Most common, especially in Congress and the courts, is simply to employ standard constitutional tools such as text, original understanding, structure, and evolving custom with regard to the specific assertion put forward. One justification for various presidents sending the armed forces into hostilities abroad without congressional authorization typically derives from a broad reading of the commander in chief clause.

By contrast, presidents in particular have engaged in a form of “foreign affairs exceptionalism,” holding that the executive enjoys a broad array of undifferentiated “foreign affairs powers” limited only by the Constitution’s grants of foreign affairs powers to the other branches. One basis for this dubious approach is paradoxically textual. Article II’s clause vesting the “executive power” in the president, on this view, doesn’t simply recognize or even grant that authority to implement statute, but is the source of any and all powers necessary to engage in the nation’s external relations. This approach is often known as the “executive vesting clause” thesis. It is wrongly attributed to founding understandings and misleadingly associated with Alexander Hamilton’s “Pacificus” essays, written during the neutrality controversy during the Washington administration. Another ostensible basis for general presidential foreign affairs authority comes from United States v. Curtiss-Wright Export Co.23 There Justice Sutherland contended that the founders understood that the president would command the broad foreign affairs authority enjoyed by the British monarch almost wholesale. Scant evidence supports this view either.24 Nonetheless, presidents ever since have miscited the case for the proposition that the executive is presumptively the “sole organ” of foreign affairs. Or, as some critics have lampooned the practice, presidents have relied on the case for the proposition, “Curtiss-Wright, therefore I’m right.”

Conflicts between Congress and the President

Nowhere has Corwin’s “invitation to struggle” been more readily accepted than in battles between Congress and the president over control of US foreign policy. Competing constitutional claims that generate genuine cases and controversies in theory should ultimately be resolved by the Supreme Court. Often the court will find ways to sidestep this duty. In Goldwater v. Carter, for example, a majority declined to address the issue of whether the president alone could terminate treaties or needed approval from either the Senate or Congress. One justice believed that the case was not “ripe”—that is, the conflict hadn’t sufficiently developed.25 Another, joined by three others, argued it presented a “political question” that the judiciary shouldn’t consider in the first place.26 In such instances, resolution of any given conflict depends on the powers of either branch to establish their position and upon their willingness to use them. Nonetheless, the Supreme Court, and with it the federal judiciary in general, have handed down numerous landmark decisions that attempt to delineate the borders between the two branches.

Without doubt the most influential precedent in this regard is Youngstown, sometimes known as the Steel Seizure Case.27 Among other things, the decision’s importance derives from the stakes it confronted at the time and, even more so, from the analytic framework it produced for later conflicts. The case arose when President Truman had the secretary of commerce issue an order for the federal takeover of the nation’s steel mills. The administration took the extreme step to maintain steel production during the Korean War in the face of a threatened national steelworkers’ strike. The court famously ruled that the Constitution did not authorize the president to take this action no matter that he believed it to be essential to the conduct of a major war. Writing for the majority, Justice Black took a straightforward textualist approach. Congress had not authorized the seizure. Nor could he claim the authority to do so as commander in chief (the war was half a world away), under his duty to take care to faithfully execute the laws (as noted, there was no law), or from his executive authority (which did not encompass seizure of property in foreign affairs emergencies).28 Justice Frankfurter augmented the analysis in a noted concurrence. Besides textual grants, it stated, the president may derive authority from an unchallenged long-standing custom. Frankfurter concluded that no such custom of emergency seizure existed for the purposes of the case, but his reasoning opened up a further possible source for executive authority.29

The opinion with enduring impact was the concurrence of Justice Jackson. Jackson’s concurrence offered a three-part analytic framework that turned on Congress’s stance toward a given assertion by the president. First, the president was at the “zenith” of his power when the action under consideration was authorized by Congress. Then the president acted pursuant to specific congressional approval in addition to any grants of power from the Constitution that may apply. By contrast, the president’s power was at its “low ebb” when the executive action faced a congressional prohibition. In this situation, the president operated based only on any direct constitutional grants. In between is a “zone of twilight,” in which Congress has neither approved nor opposed. This middle category has generally, though not entirely correctly, been taken to permit a presidential action where, as Frankfurter opined, a consistent custom of executive assertions and legislative silence exist.30

Jackson’s concurrence articulated a framework that to an extent had been implicit in prior cases and which the court has since broadly endorsed and referenced subsequently. Especially early in the nation’s history, Congress stood ready to proscribe, and the judiciary prepared to enforce, executive overreach. In Little v. Barreme, Chief Justice Marshall writing for the majority reasoned that the captain of a US Navy ship could be sued for damages for having exceeded Congress’s mandate in seizing a suspected enemy vessel during the United States’ “quasi-war” with France at the end of the 18th century.31 In another case arising out of the same conflict, Marshall likewise refused to allow another Navy captain from having a captured ship condemned as a prize, again based upon limits imposed by a federal statute during the same conflict. Slightly later, in Brown v. United States, the Marshall Court again held against the executive when it seized the property of a resident British national during the War of 1812.32 Marshall, again, concluded that Congress’s declaration of war authorized only actions consistent with the customary laws of war, which did not initially allow the seizure of property from lawful resident aliens of a belligerent.

Since Youngstown the court has frequently applied the Jackson categories to modern struggles between Congress and the president. The resulting cases, however, differ from the early national precedents in several regards. Among other things, presidential assertions since the United States rose to superpower status after World War II have become bolder. Faced with such pressure, the court’s record in keeping the executive within its constitutional and legal limits has been decidedly mixed. The pattern is evident in Dames & Moore v. Regan, a case that arose when Iranian students seized the US embassy in Tehran and held its occupants hostage.33 The decision dealing with the resolution of the crisis for the first time formally adopted a version of the Jackson Youngstown concurrence. The version it adopted, however, made it much easier to find congressional approval of, or at least acquiescence to, executive claims, thus handing the president a victory. The court has since effectively readopted the simpler Jackson framework, an approach that nonetheless has not prevented it from handing presidents periodic victories. In Trump v. Hawaii, the court noted that the Trump anti-Muslim ban rested at the “zenith” of presidential authority as it had been issued pursuant to Congress’s delegation.34 Conversely, in Zivotofsky v. Kerry (Zivotofsky II), the court acknowledged that it had to consider a “low ebb” situation, since the executive had issued certain passports in violation of a federal statute.35 The court nonetheless sided with the executive, concluding that the action fell squarely within the president’s exclusive power to recognize foreign states, which Congress could therefore not affect.

That said, the court could in important cases still apply the Youngstown framework to strike down presidential claims. Most notable in this regard is Hamdan v. Rumsfeld, which arose after the attacks of 9/11.36 To meet the crisis, President George W. Bush had issued an executive order creating military commissions, tribunals with fewer due process protections than either courts-martial or civilian courts, to try certain detainees captured in what was then called the “Global War on Terror.” This action the Supreme Court disallowed, in part because it effectively fell to the Youngstown low ebb. The court first of all rejected the claim that Congress’s blanket authorization of the use of military force authorized the action, since a more specific statute dealt with the matter. That statute was the Uniform Code of Military Justice (UCMJ), which Congress enacted under its power to regulate the armed forces. Under the court’s interpretation, the military commissions actually violated relevant provisions of the UCMJ. It further held that the military commissions violated another part of the UCMJ that incorporated into US law Common Article 3 of the Geneva Conventions, which prohibited “irregularly constituted courts” such as military commissions.

Powers of the Courts

Often underappreciated, and increasingly under challenge, the Constitution assigns the judiciary a vital role in foreign affairs. Text, original understanding, structural inference, and much of the nation’s constitutional custom confirm the idea that separation of powers applies fully to foreign affairs precisely because of the concentration of foreign affairs authority in the federal government. Just as Congress and the president are allocated significant authority in this area, so, too, are the courts. Article III, among other things, expressly extends the potential power of the federal judiciary to cases involving treaties, diplomats, admiralty and maritime jurisdiction, as well as suits between states or their citizens and foreign states and subjects. These assignments reflected one of the main reasons its supporters pushed for a new constitution—the need for the new nation to uphold its international commitments. The declaration of treaties as the supreme law of the land, along with granting the federal courts the jurisdiction to apply treaty law, furnishes one critical example. Beyond original understanding, the structural division of the federal government into three branches, with each receiving specific grants relating to foreign affairs, provides a further basis for the judiciary’s active role. Finally, early and ongoing constitutional custom reflected this commitment. It was no accident that among the Supreme Court’s initial prominent justices were leading diplomats such as John Jay and John Marshall. Ware v. Hylton, one of the court’s earliest landmark decisions, realized Madison’s goal of enforcing the treaty of peace with Great Britain in the face of state violation.37 More generally, the early court steadfastly refused to defer either to Congress or the president in the interpretation of international law.

For the most part, the judiciary continued to play its envisioned part well into the 20th century. In Asakura v. City of Seattle, for example, the Supreme Court did not hesitate to invalidate a racially discriminatory state law that violated a treaty with Japan.38 Echoing the French “quasi-war” cases, the justices in The Pacquete Habana held that the navy’s capture of small fishing vessels during the Spanish-American war violated customary international law.39 The rise of the United States from weak republic to regional, global, and finally superpower would put pressure on a sustained judicial role. Nearly constant hot and cold war from the 1940s onward would favor empowerment of the executive in particular. Presidents of both parties would push their authority to and past constitutional limits in the name of wartimeexigency and national security. With these assertions came consistent attempts to limit judicial oversight. The courts’ response has been mixed. At times the judiciary has deferred to the executive, especially when backed by Congress, even to the point of declining to take cases. At other times, however, the judiciary has asserted its own foreign affairs authority to serve as the type of check that the founders intended. This mixed record can be seen in at least three areas: access to the courts, deference to the executive, and the application of international human rights law.

Courts cannot preserve balance among the branches unless they consider the merits of cases that challenge official actions in the first place. Especially since World War II, judges themselves have more and more shut the courthouse doors in cases that they perceive to have international implications—especially though not exclusively since the turn of the millennium. In Smith v. Obama, a federal district court used a restrictive view of standing requirements to prevent consideration of President Obama’s unilateral decision to undertake military action against ISIS, a determination that echoes Kosovo and Vietnam-era precedents.40 The so-called political question doctrine has served as a basis to justify dismissing cases almost solely on the ground that they touch upon foreign policy, mostly notably in Goldwater v. Carter, in which as noted the Supreme Court ducked consideration of the Constitution’s requirements for treaty termination.41 In Kiobel v. Royal Dutch Petroleum, the court held that the Alien Tort Statute (ATS), a measure designed to protect basic rights under universal international human rights law, should be presumed not to apply outside the United States.42 In re Terrorist Attacks on September 11, 2001 and other decisions have read the Foreign Sovereign Immunity Act to have only the narrowest of exceptions to its general prohibition against suing foreign nations, even for terrorist acts and human rights violations.43 Post–9/11, the lower federal courts have vastly expanded the “state secret” bar to suit against government officials, no matter how outrageous the alleged conduct.

Conversely, high-profile counterexamples can also be cited. In Zivotofsky I, the Supreme Court reversed a decision below to hold that determining the borders between congressional and presidential authority with regard to the rendering of a birthplace on a passport was not a “political question beyond the reach of the judiciary.” The court then proved its point in Zivotofsky II, by holding in favor of the executive. In two prominent post–9/11 decisions, the court extended statutory relief to Guantanamo detainees outside the formal borders of the United States, and extended constitutional protection not long after. These and other cases indicate that the judiciary will still fulfill the duties that text, original understanding, and the bulk of constitutional custom suggest. That they are counterexamples to an opposing trend also suggests a judiciary at the crossroads.

For cases that have made it into court, a second troubling development consists of doctrines mandating judicial deference to the legal interpretations of the executive, particularly in cases involving foreign affairs. Here, too, the court appears poised to proceed down a novel and ill-advised path. In the early 21st century, the court has faced, and faced down, arguments for deference in cases turning on the Constitution, Boumedienne v. Bush; statutes, Rasul v. Bush; treaties, Hamdan v. Rumsfeld; and agency determinations, Gonzalez v. Reno.44 Arguments for courts adopting a subordinate position nonetheless have gained ever greater currency, so much so that the court itself often declares deference to be the norm even as it fails to defer. A similar pattern also appears in related areas. During the 1960s the court rejected deferring to outright executive recommendations with regard to the “act of state” doctrine, yet more recently preserved space for just such intervention with regard to foreign sovereign immunity.

As in other areas, the use of international law, including and especially when rights are at stake, has met increasing resistance. Part of the pushback, as elsewhere, results from the nation’s rise to global power and engagement in near perpetual conflict. One aspect of the challenge, in contrast to other areas, ironically stems from the greater protection of rights that international law has been expanding since World War II. Nowhere has this been more true than in the commitment of international human rights law to equality, especially racial equality, in the face of the legacy of US slavery and segregation.

The resulting controversies have been notably high profile and high-stakes in three areas. Once more, the points of contention deal with (1) treaties, (2) statutes, and (3) the Constitution itself. Conflict centers on the relationship of these categories and certain aspects of international law. With treaties, the main issue centers on whether and when such international agreements should operate as domestic law without additional legislation. Medellin v. Texas, for example, rejected the idea that a treaty to which the United States was a party bound its courts to decisions of the International Court of Justice.45 Critics divide over whether this decision undermined a historic presumption that treaties are the supreme law of the land. Regarding statutes, contention swirls around the Alien Tort Statute, which among other things incorporated customary international law to protect aliens from violations of their rights. As noted, Kiobel v. Royal Dutch Petroleum declined to apply a measure designed to implement universal international human rights law to cases that fail to touch and concern the territory of the United States.46 The Supreme Court likewise rejected decades of lower court precedent in Jesner v. Arab Bank, which held that the ATS did not authorize suits against corporations, no matter how heinous the human rights violation.47 Finally, whether foreign legal materials should be used to interpret the Constitution likewise generates controversy. The Supreme Court did just this in declaring unconstitutional the juvenile death penalty, the death penalty as applied to the mentally handicapped, and anti-homosexual sodomy statutes. Such reliance, however, produced a substantial pushback, both within the court and beyond, including influential members of Congress.48

Status of International Law in the US Domestic System

After the making of foreign policy, a second conceptual aspect of foreign affairs and a given constitutional order deals with the status of international law obligations in the domestic legal system. For an international lawyer, there are as many potential approaches to this issue as there are nation-states. At one end of the spectrum are “dualist” regimes. For these, the undertaking of an international law obligation has no force or bearing within the domestic courts or domestic law in general. A state, for example, may violate the International Covenant on Civil and Political Rights (ICCPR), but a victim would not be able to assert the treaty violation in any of the state’s legal forums. International obligations, such as acceding to a treaty, become part of domestic law only if they are incorporated through an additional domestic process, usually a statute passed by the national legislature. Almost all of the world’s anglophone, common law systems are dualist since this has long been the position in the United Kingdom and so its former colonies. At the other end of the spectrum, “monist” states embrace international law commitments more immediately and thoroughly. For these, the international obligation becomes part of the domestic legal system without any further process or legislation. The Netherlands exemplifies states that have adopted this type of monist approach. There a victim of the ICCPR could argue an alleged treaty violation in the first instance.

International Agreements

As for the United States, the answer is complicated. The Constitution’s text appears to diverge from British rule and announce a monist system: “Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land” along with federal statutes and the Constitution itself.49 Two hundred years of interpretation and practice have instead yielded a system that would mystify a foreign observer. The US approach in the first instance turns on whether a given international obligation arises from an agreement or customary international law. Within each category there is a partial correlation between how the United States undertook the obligation—a threshold separation of powers question—and whether the obligation has force in US domestic law—the status issue.

The Constitution specifies only one way the nation can enter into an international agreement: the “President . . . shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur.” In fact, three methods exist: (1) treaties, (2) congressional-executive agreements, and (3) sole executive agreements. Of these, treaties have presented the most questions and twists. As an initial matter, the treaty clause addresses the threshold separation of powers question of how the United States makes treaties with the curious combination of the president and a supermajority of the Senate. The Federal Convention initially had vested the power in the Senate alone, but then reassigned the task of treaty-making to the president, in part on the ground that a single official would be better placed to conduct negotiations. The Senate remained in its advice and consent role, among other reasons, because treaties would be automatically part of US law. Despite this, the founders did not include the House of Representatives on the grounds that it would be too numerous, less cosmopolitan, and too likely to betray secrecy when needed. It may therefore appear that the two-thirds requirement for Senate approval was intended to make up for the resulting “democratic deficit.” In truth, the supermajority requirement came about to address the fears of the states that New England and the Middle States may sacrifice US navigation rights controlled in succession by Spain and France in exchange for transatlantic commercial concessions. At the time, a one-third plus one veto would have been enough to block such a regional “sellout.”50

Once made, US treaties present a host of issues relating to their domestic status. Despite the supremacy clause, Chief Justice Marshall fairly early in Foster v. Neilson reasoned that not all treaties in fact applied in monist fashion as federal law.51 Rather, those that would in some form apply as federal law immediately would be known as “self-executing” treaties; those that required incorporation into domestic law by Congress would be termed “non-self-executing” treaties. For Marshall, a key to distinguishing between the two turned on the intention of the treaty-makers, especially as expressed in a treaty’s language. Given the supremacy clause, many commentators considered that treaties were presumptively self-executing unless there was an intention to the contrary. The Senate, as part of the treaty-making process, has typically expressed such an intention with “declarations of non-self-execution” when approving international human rights treaties. To the extent this presumption for self-execution persisted, the Medellin decision has muddled the picture.52 This decision read the United Nations Charter as non-self-executing with regard to the immediate domestic applicability of International Court of Justice decisions. The majority came to this conclusion citing, among other things, the absence of clear language indicating self-executing, language Justice Breyer’s dissent pointed out could never be found in a multilateral treaty given the number of dualist states in the world.53 To what extent Medellin affects the traditional analysis remains to be seen. Beyond this, at least one prominent scholar has argued that the doctrine originally applied only to application of treaties for Federal purposes and did not affect the rule that any treaty, self-executing or not, would be supreme over state laws.54 However settled this position was, this distinction disappeared not long after World War II. Thanks in part to racially motivated fears in the Senate, non-self-executing human rights treaties that make equality a cornerstone do not preempt state law without a subsequent act of Congress.

Once deemed self-executing, treaties present the further question of hierarchy. Other than order, the supremacy clause does not specify the relationship between treaties, federal statutes, and the Constitution. The answers to this question came surprisingly late. Not until the late 19th century did the Supreme Court hold that treaties and self-executing treaties were equivalent.55 As between statutes, conflict between a federal law and treaty would ordinarily be determined via the last-in-time rule. That said, in only one case has the Supreme Court struck down a statute for conflict with a subsequent treaty.56 As for the Constitution, its supremacy over both may appear obvious. Indeed, Marbury v. Madison reflects—but hardly established—the idea that constitutions are superior to statutes.57 Not until the mid-20th-century decision in Reid v. Covert did the court confirm the same idea for international agreements, and then not entirely directly.58 This hierarchy, it should be noted, established a twofold possibility for international law violations. On the international plane a treaty is by definition binding. Domestically, however, the United States may violate the obligation if either the Constitution or a later-in-time statute is inconsistent with the agreement. This is one reason why the president or Senate will often make reservations to treaty provisions that could be seen as imposing unconstitutional obligations.

US constitutional law affords one more distinctive feature with regard to treaties. As noted, the system presupposes that the federal government can operate based only on legitimate constitutional grants, whether through express text, implied powers that are means to implement enumerated powers, the necessary and proper clause, original understanding, or custom. For domestic matters, the doctrine of federalism holds that those powers not granted to the federal government are left to the states. This combination of limited if extensive grants, combined with federalism, raises a question: can Congress reach matters in implementing a treaty that it could not otherwise reach? In other words, can treaties augment the federal government’s domestic power? Justice Oliver Wendell Holmes Jr. answered yes in Missouri v. Holland.59 There the court assumed that Congress could not regulate migratory birds under and domestic grant of power. Yet it upheld legislation that did just this that incorporated provisions of a treaty with the United Kingdom on behalf of Canada. Those who favor state power have subjected Holland to substantial criticism. The court, however, sidestepped overruling it, and it formally remains standing precedent.

For all the complexity of treaty law, congressional-executive agreements are by far the most popular mechanism through which the United States enters into compacts with other states. As the name implies, the president negotiates an agreement with the approval of both the Senate and House by a simple majority. In fact, in the vast majority of congressional-executive agreements the president negotiates with prior congressional approval. Either way, they are easier to obtain than classic treaties. Though unmentioned in the Constitution, congressional-executive agreements date back to the earliest days of the republic. With steady growth, they surpassed treaties during the 19th century and skyrocketed after World War II. A typical example was the North American Free Trade Agreement (NAFTA) between the United States, Canada, and Mexico. This agreement actually triggered a late-in-the-day, high-profile debate concerning the legitimacy of the device. If nothing else, congressional-executive agreements rest on such long-standing custom that they are here to stay. As a final point, the separation of powers aspects of these agreements effectively answer the domestic status question. Given that they are concluded in the same manner as a federal statute, without more a congressional-executive agreement will at once bind the nation internationally and have immediate effect domestically.

Sole executive agreements represent the final way the United States enters into what in international law would be called a “treaty.” The label makes the separation of powers manifest: the president alone concludes these instruments. These, too, find no mention in the Constitution but have nonetheless been around since the nation’s earliest days and derive their legitimacy through long-standing custom. As that custom has developed, they are generally confined to facilitating the exercise of express presidential foreign affairs powers. SOFAs, or Status of Forces Agreements, which define the powers and immunities of US troops stationed in other countries, are understood to implement the president’s commander in chief authority. Likewise, agreements to liquidate claims upon new regimes have been justified as a corollary to the executive authority to recognize regimes through the power to receive ambassadors. As for domestic status, the Supreme Court has settled that sole executive agreements, despite the lack of congressional participation, have the immediate force of law, including supremacy over state law.60

Customary International Law

Customary international law provides the other major source of international norms that can apply within the US legal system. A state consents to this form of obligation passively. Unless it engages in persistent and timely objection to an emerging international rule, it is bound. It should not come as a surprise that the Constitution does not assign to any of the branches, alone or in combination, the power to engage in passive consent. The text does, however, refer to this body of law by its approximate 18th-century equivalent: “the law of nations.” Specifically, the Constitution assigns to Congress the power to define and punish offenses against the law of nations. The law of nations does not, however, appear alongside the Constitution, laws, and treaties in the supremacy clause. As a result, courts have had to grapple with the domestic status of customary international law. Their efforts may usefully be divided into “direct” and “indirect” application of international custom.

“Direct” application of customary international law may be defined as its use in domestic courts without incorporation by Congress. American courts had directly applied the law of nations in this sense since before independence. In contrast to treaties, the British view was essentially monist. The law of nations, natural law, and the common law formed distinct yet interrelated sources from which courts would discern and refine legal rules. The law of nations formed an especially important branch, encompassing admiralty, prize, and merchant rules that were cornerstones of a maritime economy and naval warfare. For much of the nation’s history, the federal judiciary applied law of nations rules even without legislative incorporation. This practice complemented the direct judicial application of general federal common law in domestic matters. A late, yet iconic, landmark example is The Pacquete Habana, in which the courts directly applied prize law, famously announcing that, “international law is part of our law.”61 The repudiation of general federal common law in Erie R.R. v. Tompkins raised the question of whether this meant the repudiation of customary international law as well.62 The Supreme Court more or less gave an answer in the Delphic case Banco Nacional de Cuba v. Sabbatino.63 Justice Harlan’s difficult opinion remains open to many interpretations. One that arguably brings some coherence to the issue holds that the judiciary may no longer directly apply customary international law, but retains a power to create rules based upon customary international law as a function of its post-Erie power to make federal common law in certain situations.

“Indirect” applicability of customary international law for present purposes simply means that Congress decided to incorporate it by legislation. Here the most prominent example is the Alien Tort Statute. Enacted by the first Congress, the ATS provides that the district courts shall have jurisdiction over civil cases brought by aliens for a tort only in violation of the law of nations or treaties of the United States. Dormant for almost two centuries, the ATS became a vehicle for foreigners to sue officials of repressive regimes for international human rights violations. In Sosa v. Alvarez-Machain, the Supreme Court broadly endorsed the practice, reasoning that the first Congress expected the courts to fashion causes of actions based on customary international law violations that commanded an international consensus and were specific.64 Since then, however, the court drastically cut back on ATS litigation, confining it to suits that touch and concern the territory of the United States and rejecting corporate liability.

Two important legal standards illustrate the complexities of addressing customary international law, and related foreign affairs concerns, within the US legal system. The “act of state” doctrine, for one, holds that the courts of one sovereign state should not question the official acts of another government conducted within its own territory, unless those acts violate international law. The Supreme Court in Sabbatino denied that the doctrine was established as customary international law. Even if not, many, though by no means all, commentators have interpreted the decision to hold that the federal courts could fashion federal common law rules directly derived from customary international law or national foreign affairs considerations more generally. Foreign sovereign immunity doctrine, by contrast, holds that a sovereign state is immune from suit in the courts of another government. This rule is undisputedly established in customary international law and was applied as such by the federal courts for nearly all the nation’s history. Disputes on how to do so nonetheless arose during the 20th century, both with regard to how broad a version of foreign sovereign immunity to apply, as well as the role of the executive in guiding the judiciary’s determinations. Congress for the most part resolved these issues in 1976 with the passage of the Foreign Sovereign Immunities Act (FSIA), which for the most part incorporated a narrower, “restrictive” version of the doctrine, which allows states to be sued when operating in a commercial capacity. As such, the FSIA stands as a more contemporary example of the “indirect” application of customary international law in the US legal system.

Finally, customary international law may influence US domestic law obliquely. Murray v. the Schooner Charming Betsy established a principle that “an act of Congress ought never to be construed to violate the law of nations if any other possible construction remains.”65 Articulated by Chief Justice Marshall, the “Charming Betsy canon” has been honored, if sometimes in the breach, ever since.

Full Circle: Federalism Concerns

As the founders envisioned, several states have played a comparatively marginal role in the nation’s foreign affairs. As noted, the Constitution grants the federal government a virtual monopoly in dealing with other countries. Among other things, the Supreme Court has consistently overturned state measures that conflict with the Constitution, federal statutes, or self-executing treaties or other international agreements. In one controversial case, the court even invalidated a state law that conflicted with “dormant” federal foreign affairs power in the absence of any actual federal measure to the contrary.66 States have exercised their express constitutional authority to conclude “compacts” with foreign nations with Congress’s approval. Private international law treaties are crafted in a way that depend on the acceptance of US states. The Senate also routinely attaches “federalism” understandings to its approval of treaties that indicate any domestic implementation shall be only the extent that Congress exercises legislative and judicial jurisdiction. Given Congress’s still vast powers under the commerce clause, as well as the court’s holding in Missouri v. Holland, it is unclear whether such provisions have any real meaning. All in all, Justice Sutherland only slightly exaggerated in stating that in US foreign relations, “the State of New York”—and the states generally—“does not exist.”67

Discussion of the Literature

Writing on US foreign relations, long a secondary area of constitutional scholarship, now stands as among its most vibrant and widely covered areas.

Certain earlier work nonetheless endures. Frederick Marks’s Independence on Trial remains among the few, and leading, monographs about the foreign relations dimensions of the Constitution’s framing.68 More generally, Edward S. Corwin’s insightful studies of presidential powers, the United States and world organization, and war powers, remain useful background references.69 So, too, does the American Law Institute’s landmark Restatement of the Law Third: The Foreign Relations Law of the United States, a literal reference work of significant influence, that has been succeeded by a partial fourth Restatement.70

Scholarship since the 2000 has both expanded and transformed the field nonetheless, focusing on the subject’s two major themes: separation of powers in the making of foreign policy, and the status of international law within the US legal system. For each issue, the rise of the nation as a superpower, the military and diplomatic conflicts that have resulted, and the response to the attacks of 9/11 have promoted what had been a scholarly backwater to a preeminent field of study. The resulting scholarship has drawn upon, been fueled by, and replicates the divisions in work on domestic constitutional law that addresses parallel questions “one level down,” that is, separation of powers in domestic policymaking and the proper balance of federal and state law and authority.

Separation of powers scholarship tends to divide between work that emphasizes and celebrates the president’s role in foreign affairs versus writing that stresses the influence of Congress, and, to a lesser extent, of the federal courts. “Presidentialist” work dominates, in part because many authors are veterans of the executive branch. Whatever their differences, this view includes such leading scholars as Anthony Bellia, Bradford Clark, Jack Goldsmith, Andrew Kent, Julian Ku, Saikrishna Prakash, Eric Posner, Michael Ramsey, Adrian Vermeule, and John Yoo.71 Their works advocate, reflect, or complement the idea of a so-called unitary executive. On this view, the president should rightly and all but unilaterally dominate decision-making in foreign affairs. Countering this school include such “congressionalist” (or even “trinitarian”) commentators as Bruce Ackerman, Curtis Bradley, Martin Flaherty, David Golove, Daniel Hulsebosch, Heidi Kitrosser, Martin Lederman, Thomas Lee, Julian Mortenson, Deborah Pearlstein, David Rudenstine, Gordon Silverstein, David Sloss, and Beth Stephens.72

Accounts likewise divide with respect to the degree the nation has been committed to international law. Here “sovereigntists,” echoing domestic “states’ rights” narratives, emphasize—and advocate—historic American exceptionalism with regard to international standards and institutions. Most, though by no means all, presidentialist scholars tend to be sovereigntist. “Internationalist” scholars, who themselves are usually congressionalist, interpret foreign relations history with an emphasis on the nation’s adherence to international commitments. Louis Henkin, Harold Koh, Anne-Marie Slaughter, and Sarah Cleveland are among the leading scholars who have made the internationalist case.73 Internationalist in a different and innovative way is Mary Dudziak’s Cold War Civil Rights, pioneering the influence of foreign relations on the domestic struggle for civil rights.74

Certain general studies that stand apart from current scholarly debates also deserve mention. Of these, George C. Herring’s From Colony to Superpower provides a sweeping and invaluable overview.75 Other general studies usefully embrace almost every current scholarly perspective. Especially useful in this regard is the kaleidoscopic International Law in the U.S. Supreme Court, edited by William Dodge, Michael Ramsey, and David Sloss.76 For a balanced, concise yet comprehensive overview of jurisprudence in the early 21st century, there is perhaps no better starting point than Curtis Bradley’s International Law in the U.S. Legal System.77

Primary Sources

Farrand, Max, ed. The Records of the Federal Convention of 1787. Rev. ed. 4 vols. New Haven, CT: Yale University Press, 1966.Find this resource:

Kaminski, John P., et al., eds. The Documentary History of the Ratification of the Constitution. 29 vols. Madison: Wisconsin Historical Society Press,1976–.Find this resource:

US Department of State. “Historical Documents: The Foreign Relations of the United States, 1861–.” Office of the Historian, Bureau of Public Affairs.Find this resource:

Library of Congress. “American State Papers, 1789–1838.”Find this resource:

Further Reading

Ackerman, Bruce. The Decline and Fall of the American Republic. Cambridge, MA: Belknap Press of Harvard University Press, 2013.Find this resource:

American Law Institute. Restatement of the Law Fourth: The Foreign Relations Law of the United States. Saint Paul, MN: American Law Institute Publishers, 2018.Find this resource:

Bradley, Curtis A. International Law in the U.S. Legal System. 2nd ed. New York: Oxford University Press, 2015.Find this resource:

Dudziak, Mary L. Cold War Civil Rights: Race and the Image of American Democracy. New ed. Princeton, NJ: Princeton University Press, 2011.Find this resource:

Flaherty, Martin S. Restoring the Global Judiciary: Why the Supreme Court Should Rule in U.S. Foreign Affairs. Princeton, NJ: Princeton University Press, 2019.Find this resource:

Goldsmith, Jack. Power and Constraint: The Accountable Presidency After 9/11. New York: W. W. Norton, 2012.Find this resource:

Henkin, Louis. Foreign Affairs and the US Constitution. 2nd ed. Oxford: Clarendon Press, 1996.Find this resource:

Herring, George C. From Colony to Superpower: U.S. Foreign Relations Since 1776. Oxford: Oxford University Press, 2008.Find this resource:

Koh, Harold Hongju. The National Security Constitution: Sharing Power After the Iran-Contra Affair. New Haven, CT: Yale University Press, 1990.Find this resource:

Ramsey, Michael D. The Constitution’s Text in Foreign Affairs. Cambridge, MA: Harvard University Press, 2007.Find this resource:

Silverstein, Gordon. Imbalance of Powers: Constitutional Interpretation and the Making of American Foreign Policy. New York: Oxford University Press, 1996.Find this resource:

Sloss, David L. The Death of Treaty Supremacy: An Invisible Constitutional Change. New York: Oxford University Press, 2016.Find this resource:

Sloss, David L., Michael D. Ramsey, and William S. Dodge, eds. International Law in the U.S. Supreme Court: Continuity and Change. New York: Cambridge University Press, 2011.Find this resource:

White, G. Edward. “The Transformation of the Constitutional Regime of Foreign Relations.” Virginia Law Review 85, no. 1 (1999): 1–150.Find this resource:

Yoo, John. Crisis and Command: A History of Executive Power from George Washington to George W. Bush. New York: Kaplan, 2010.Find this resource:


(3.) Edward S. Corwin, The President: Office and Powers, 1787–1984, ed. Randall W. Bland, Theodore T. Hindson, and Jack W. Peltason, 5th rev. ed. (New York: New York University Press, 1984), 201.

(4.) 343 U.S. 579, 643 (1952) (Jackson, J., concurring).

(5.) 343 U.S. at 503, 610 (Frankfurter, J., concurring).

(6.) Jack P. Greene, The Constitutional Origins of the American Revolution (New York: Cambridge University Press, 2011); and John Phillip Reid, Constitutional History of the American Revolution, 4 vols. (Madison: University of Wisconsin Press, 1986–1991).

(7.) John Quincy Adams, “An Oration: Upon the Importance and Necessity of Public Faith, to the Well-Being of a Community” (commencement speech, Harvard University, Cambridge, MA, July 18, 1787).

(8.) Frederick W. Marks III, Independence on Trial: Foreign Affairs and the Making of the Constitution (Wilmington, DE: Scholarly Resources, 1986).

(9.) See Gordon S. Wood, The Creation of the American Republic, 1776–1787 (Chapel Hill: University of North Carolina Press, 1969), 403–407.

(12.) U.S. Const. art. I.

(13.) U.S. Const. art. II.

(14.) U.S. Const. arts. III & VI.

(15.) Chae Chan Ping v. United States, 130 U.S. 581 (1889) (upholding exclusion); and Fong Yue Ting v. United States, 149 U.S. 698 (1893) (upholding deportation).

(17.) See Martin S. Flaherty, “The Story of the Neutrality Controversy: Struggling Over Presidential Power Outside the Courts,” in Presidential Power Stories, ed. Christopher H. Schroeder and Curtis A. Bradley (New York: Foundation Press, 2008), 21–52.

(18.) Durand v. Hollins, 8 F. Cas. 111 (No. 4,186) (1860).

(19.) Durand v. Hollins, 8 F. Cas. 111 (No. 4,186) (1860).

(20..) 67 U.S. 635 (1863).

(21.) Youngstown, 343 U.S. at 582–584.

(22.) Goldwater v. Carter, 444 U.S. 996 (1979).

(23.) 299 U.S. 304 (1936).

(24.) See Curtis A. Bradley and Martin S. Flaherty, “Executive Power Essentialism and Foreign Affairs,” Michigan Law Review 102, no. 4 (2004): 545.

(25.) Goldwater, 444 U.S. at 997 (Powell, J., concurring).

(26.) Goldwater, 444 U.S. at 1002 (Rehnquist, J., concurring).

(27.) 343 U.S. 579 (1952).

(28.) Youngstown, 343 U.S. at 582.

(29.) Youngstown, 343 U.S. at 593 (opinions of Frankfurter, J.).

(30.) Youngstown, 343 U.S. at 634 (opinion of Jackson, J.).

(31.) 6 U.S. (2 Cranch) 170 (1804).

(32.) 12 U.S. (8 Cranch) 110 (1814).

(33.) 453 U.S. 654 (1981).

(34.) 585 U.S. __ (2018).

(35.) 576 U.S. __ (2015).

(36.) 548 U.S. 557 (2006).

(37.) 3 U.S. (3 Dall.) 199 (1796).

(38.) 265 U.S. 332 (1924).

(39.) 175 U.S. 677 (1900).

(40.) No. 16–843 (CKK) (D.D.C. November 21, 2016). The Court of Appeals for the DC Circuit, in an unpublished opinion, later affirmed the dismissal on the ground that the case had become moot. Smith v. Trump, 731 Fed.Appx. 8 (Mem) (2017).

(41.) Goldwater, 444 U.S. 996.

(42.) 569 U.S. 108 (2013).

(43.) 714 F.3d 659 (2nd Cir. 2013).

(44.) Boumedienne v. Bush, 553 U.S. 723 (2008); Rasul v. Bush, 542 U.S. 466 (2004); Hamdan, 548 U.S. 557; and Gonzalez v. Reno, 212 F.3d 1338 (2000), cert. denied, 530 U.S. 1270 (2000).

(45.) 552 U.S. 491 (2008).

(46.) Kiobel, 569 U.S. 108.

(47.) 584 U.S. __ (2018).

(48.) Atkins v. Virginia, 536 U.S. 304 (2002); and Roper v. Simmons, 543 U.S. 551 (2005) (invalidating the juvenile death penalty).

(49.) U.S. Const. art. VI, cl. 2.

(50.) See Flaherty, Restoring the Global Judiciary, chapter 3.

(51.) 27 U.S. (2 Pet.) 253 (1829).

(52.) Medellin, 552 U.S. 491.

(53.) Medellin, 552 U.S. at 538 (Breyer, J., dissenting).

(55.) Whitney v. Robertson, 124 U.S. 190 (1888).

(56.) Cook v. United States, 288 U.S. 102 (1933).

(57.) 5 U.S. (1 Cranch) 137 (1803).

(58.) 354 U.S. 1 (1957).

(59.) State of Missouri v. Holland, 252 U.S. 416 (1920).

(60.) United States v. Belmont, 301 U.S. 324 (1937); and United States v. Pink, 315 U.S. 203 (1942).

(61.) Pacquete Habana, 175 U.S. at 700.

(62.) 304 U.S. 64 (1938).

(63.) 376 U.S. 398 (1964).

(64.) 542 U.S. 692 (2004).

(65.) 6 U.S. (2 Cranch) 64 (1804).

(66.) Zschernig v. Miller, 389 U.S. 429 (1968).

(67.) United States v. Belmont, 301 U.S. 324, 329.

(68.) Marks, Independence on Trial.

(69.) Corwin, The President, 201; Edward S. Corwin, Total War and the Constitution (New York: A. A. Knopf, 1947); and Edward S. Corwin, The Constitution and World Organization (Princeton, NJ: Princeton University Press, 1944).

(70.) American Law Institute, Restatement of the Law Third: The Foreign Relations Law of the United States, 2 vols. (Saint Paul, MN: American Law Institute Publishers, 1987); and American Law Institute, Restatement of the Law Fourth: The Foreign Relations Law of the United States (Saint Paul, MN: American Law Institute Publishers, 2018).

(71.) See, for example, Anthony J. Bellia Jr. and Bradford R. Clark, The Law of Nations and the United States Constitution (New York: Oxford University Press, 2017); Jack Goldsmith, Power and Constraint: The Accountable Presidency After 9/11 (New York: W. W. Norton, 2012); Andrew Kent, “Congress’s Under-Appreciated Power to Define and Punish Offenses Against the Law of Nations,” Texas Law Review 85 (2007): 843; Julian G. Ku, “The Prospects for the Peaceful Co-Existence of Constitutional and International Law,” Yale Law Journal Online 119 (2009): No. 15; Saikrishna Bangalore Prakash, Imperial from the Beginning: The Constitution of the Original Executive (New Haven, CT: Yale University Press, 2015); Eric A. Posner and Adrian Vermeule, The Executive Unbound: After the Madisonian Republic (New York: Oxford University Press, 2011); Michael D. Ramsey, The Constitution’s Text in Foreign Affairs (Cambridge, MA: Harvard University Press, 2007); and John Yoo, Crisis and Command: A History of Executive Power from George Washington to George W. Bush (New York: Kaplan, 2010).

(72.) See, for example, Bruce, The Decline and Fall of the American Republic (Cambridge, MA: Belknap Press of Harvard University Press, 2013); Bradley and Flaherty, “Executive Power Essentialism”; Flaherty, Restoring the Global Judiciary; David M. Golove and Daniel J. Hulsebosch, “A Civilized Nation: The Early American Constitution, the Law of Nations, and the Pursuit of International Recognition,” New York University Law Review 85, no. 4 (2010): 932–1066; Heidi Kitrosser, Reclaiming Accountability: Transparency, Executive Power, and the U.S. Constitution (Chicago: University of Chicago Press, 2015); Thomas H. Lee, “The Safe-Conduct Theory of the Alien Tort Statute,” Columbia Law Review 106, no. 4 (2006): 830–908; Julian Davis Mortenson, “Executive Power and the Discipline of History,” University of Chicago Law Review 78, no. 1 (2011): 377–443; Deborah N. Pearlstein, “After Deference: Formalizing the Judicial Power for Foreign Relations Law,” University of Pennsylvania Law Review 159, no. 3 (2011): 783–852; David Rudenstine, The Age of Deference: The Supreme Court, National Security, and the Constitutional Order (New York: Oxford University Press, 2016); Gordon Silverstein, Imbalance of Powers: Constitutional Interpretation and the Making of American Foreign Policy (New York: Oxford University Press, 1996); David L. Sloss, The Death of Treaty Supremacy: An Invisible Constitutional Change (New York: Oxford University Press, 2016); and Paul Hoffman and Beth Stephens, “International Human Rights Cases Under State Law and in State Courts,” UC Irvine Law Review 3, no. 1 (2013): 9–23.

(73.) See, for example, Henkin, Foreign Affairs and the US Constitution; Harold Hongju Koh, The Trump Administration and International Law (New York: Oxford University Press, 2018); Anne-Marie Burley (Slaughter), “The Alien Tort Statute and the Judiciary Act of 1789: A Badge of Honor,” American Journal of International Law 83, no. 3 (1989): 461–493; and Sarah H. Cleveland, “Our International Constitution,” Yale Journal of International Law 31, no. 1 (2006): 1–125.