He brings with him, abroad, a new sense of strategic vision. Obama’s critics should give him a break for having to govern in a time of anarchy and limited choices. But he compounded regional crises by laying down red lines, for instance on the use of chemical weapons, that he then allowed dictators to cross. He hung back from action in Syria, yet aided the revolt against Gadhafi in Libya.

And his centerpiece deal with Iran came at a heavy price: the slow expansion of Tehran’s influence throughout the region. No wonder Gulf states desire greater US involvement, and Benjamin Netanyahu, Prime Minister of Israel, praised the US Tomahawk strike on a Syrian airstrip.

This is what Trump is doing that Obama was reluctant to do: He’s picking sides. The choices are not ideal. Who would want to ally with Saudi Arabia, a fossilized monarchy that won’t even let women drive, which has long been accused of itself exporting extremism? On the other hand, when Saudi Arabia is in a proxy war with Iran in Yemen, it is at least coherent and rational to sell arms to the Saudis.