Donald Trump’s emergence as an electable candidate for the US presidency marks the definitive end of the ‘post’ era — that is, post-World War II, post-Cold War, post-unipolar moment. This would have been the case even if Hillary Clinton had won. Trump’s election on 8 November simply added an exclamation point.Through their support for Trump, too many Americans declared that the onerous posture of global leadership that the United States had sustained for 70 years as on balance, in American interests, no longer worked for them.