Despite national differences, the military has usually presented a lack of political role and agency in the United Arab Emirates (UAE), Qatar, Kuwait, and Oman. This development has occurred because state formation in these nations has been mainly driven by energy revenues and external security provision. The primary task of the armed forces, especially between the 1950s and the 1970s, was rulers’ protection and regime security; for the monarchies, keeping the armies small and detached from political power was a coup-proofing strategy. As a result, researchers used to stress the dependency linkage between tribal armies and royal families, underlining the prominence of kinship loyalties (for upper echelons) and foreign manpower (for lower ones) in political–military relations. But as in a prism, these militaries reveal three coexistent faces—praetorian, neopatrimonial, and performative—with one prevailing on the others depending on the time frame. In fact, starting from the 1990s, the gradual processes of state consolidation and modernization have fostered the expansion of the military sector in the Arab Gulf states, maximizing the neopatrimonial dimension of the military. Defense procurement burgeoned, with an emphasis on hard power, as the agreements with the United States and Western allies to establish defense pacts, troop stationing, and military facilities. In the context of state transformation, the 2010s represent a turning point for the militaries that showed a rising performative dimension, especially in the UAE, and, to a lesser extent, Qatar—performative because of greater operative performances and also because of the ability to influence nation-building. Arab Gulf states’ national strategies acquired a military shape, reflecting in some cases military-driven foreign policies. Autonomy and self-reliance became national guiding stars and military reform was no longer a taboo for Emirati, Qatari, and Kuwaiti rulers. In fact, this is now functional in the improvement of military capabilities through know-how transfer, local expertise, and forms of social mobilization (as conscription, parades, exhibitions, and official rhetoric). In this sense, Oman played a vanguard role in the 1970s as the first-ever example of a performative army in the Gulf monarchies. In the performative armies of the 2010s, soldiers embody a renewed model of post-oil citizenship, based on sacrifice, duty, and national pride. As a matter of fact, the 2015 unprecedented military intervention in Yemen has turned into a watershed for Gulf militaries’ tasks and capabilities (especially for the UAE). Therefore, the military has gradually become a tool of nation-building and governments have been betting on militarized nationalism to forge a sense of shared belonging, identity, and patriotism. In times of rising Middle Eastern arms races and multidimensional threats, the military dimension has been redrawing civil–military relations, especially in the UAE and Qatar, thus offering a new research agenda for future studies on the Arab Gulf states’ militaries.