Why is Trump radically transforming American foreign policy? The United States needs to change its strategy because it no longer has the resources to implement a policy of wide-ranging intervention, as in the past. Moreover, the disastrous Bush wars have reduced Americans’ confidence in solving others’ crises via military intercession. So America now focuses on basic national interests and the challenge posed by China, on which its future depends. Will Trump succeed in being re-elected in such circumstances? The support of the Heartland may no longer be sufficient, and Trump needs to win over independent voters. The Democratic Party has a good chance at victory if it manages to mobilise its electorate and choose an authoritative candidate.

Giuseppe Mammarella is professor emeritus at Stanford University.