Economic envy, once seen as a European vice, is now rife. The rich appear in Barack Obama’s speeches not as entrepreneurial role models but as modern versions of the “malefactors of great wealth” denounced by Teddy Roosevelt a century ago... Globalisation is under fire: free trade is less popular in the US than in any other developed country, and a nation built on immigrants is building a fence to keep them out...

America has got into funks before now. In the ’50s it went into a Sputnik-driven spin about Soviet power; in the ’70s there was Watergate, Vietnam and the oil shocks; in the late ’80s Japan seemed to be buying up America. Each time, the US rebounded, because the country is good at fixing itself. Just as American capitalism allows companies to die, and to be created, quickly, so its political system reacts fast. In Europe, political leaders emerge slowly, through party hierarchies; in America, the primaries permit inspirational unknowns to burst into the public consciousness from nowhere. Still, countries, like people, behave dangerously when their mood turns dark. If America fails to distinguish between what it needs to change and what it needs to accept, it risks hurting not just allies and trading partners, but also itself.

Excerpted from a leader in ‘The Economist’