So Donald Trump went to a NATO summit, insulted our allies, then made the absurd demand not just that they increase defense spending — which they should — but that they raise it to 4 percent of G.D.P., much higher than the bloated military spending in his own budget. He then claimed, falsely, to have won major concessions, and graciously declared that it is “presently unnecessary” to consider quitting the alliance.

Was there anything our allies could have done that would have mollified him? The answer, surely, is no. For Trump, disrupting NATO doesn’t seem to be a means to an end; it’s an end in itself.

Does all of this sound familiar? It’s basically the same as the story of the escalating trade war. While Trump rants about other countries’ unfair trade practices — a complaint that has some validity for China, although virtually none for Canada or the European Union — he hasn’t made any coherent demands. That is, he has given no indication what any of the countries hit by his tariffs could do to satisfy him, leaving them with no option except retaliation.

So he isn’t acting like someone threatening a trade war to win concessions; he’s acting like someone who just wants a trade war. Sure enough, he’s reportedly threatening to pull out of the World Trade Organization, the same way he’s suggesting that the U.S. might pull out of NATO.