For the past 50 years, American leaders have been supremely confident that they could suffer military setbacks in places like Cuba or Vietnam without having their system of global hegemony, backed by the world’s wealthiest economy and finest military, affected. The country was, after all, the planet’s “indispensible nation,” as Secretary of State Madeleine Albright proclaimed in 1998 (and other presidents and politicians have insisted ever since). The . enjoyed a greater “disparity of power” over its would-be rivals than any empire ever, Yale historian Paul Kennedy announced in 2002. Certainly, it would remain “the sole superpower for decades to come,” Foreign Affairs magazine assured us just last year. During the 2016 campaign, candidate Donald Trump promised his supporters that “we’re gonna win with military… we are gonna win so much you may even get tired of winning.” In August, while announcing his decision to send more troops to Afghanistan, Trump reassured the nation: “In every generation, we have faced down evil, and we have always prevailed.” In this fast-changing world, only one thing was certain: when it really counted, the United States could never lose.