Summary

The US government’s perception of and response to international terrorism has undergone momentous shifts since first focusing on the issue in the early 20th century. The global rise of anarchist and communist violence provided the impetus for the first major US government programs aimed at combating international terrorism: restrictive immigration policies targeting perceived radicals. By the 1920s, the State Department emerged as the primary government agency crafting US responses to international terrorism, generally combating communist terrorism through diplomacy and information-sharing partnerships with foreign governments. The 1979 Iranian hostage crisis marked the beginning of two key shifts in US antiterrorism policy: a heightened focus on combating Islamist terrorism and a willingness to deploy military force to this end. The terrorist attacks of September 11, 2001, led US officials to conceptualize international terrorism as a high-level national security problem, leading to US military invasions and occupations of Afghanistan and Iraq, a broader use of special forces, and unprecedented intelligence-gathering operations.