If you’re looking for a single-sentence summation of the change in America’s foreign policy under Donald Trump, you could do worse than what Trump said on Wednesday: “The European Union was formed in order to screw the United States. That’s the purpose of it. And they’ve done a good job of it. But now I’m president.” Trump seems to loathe America’s traditional European allies even as he warms relations with Russia. He’s threatened tariffs on Canada and Mexico while softening his rhetoric on China. And he seems fixated on the idea of territorial expansion — whether it’s the Panama Canal, Greenland or even Gaza.   There is a “Trump doctrine” emerging here. It’s one that could be glimpsed dimly in Trump’s first term but is exploding to the fore in his second. What will it mean for the world? What will it mean for the United States? Fareed Zakaria is the host of CNN’s “Fareed Zakaria GPS,” a columnist for The Washington Post and the author of the best-selling “Age of Revolutions.” He’s one of the clearest foreign policy thinkers around, and he doesn’t disappoint here. This episode contains strong language.