The projection of military power has been identified as the key strategic function of the armed forces since the Gulf War (1991). Before this conflict, the Cold War had imposed a model of armed forces able to handle a massive blow coming from the East. Granted, the US intervened in Vietnam and several European countries conducted small-scale operations in Africa, but this was not their primary function. The Gulf War revealed a change in this function, and triggered the beginning of the “projection era”. With the collapse of the Warsaw Pact, western armies adapted to the newly identified strategic function: project military power worldwide. In effect, this meant being interoperable with the United States (in order to be able to participate in a multinational military intervention, unilateralism becoming gradually illegitimate in the post-Cold War international system), and going through a US-led process of military transformation. Western states adjusted to this process at different paces, but the key point is that power projection was the driver of military change. Like many others, I believe that this era is coming to an end, for several reasons.