'He Just Wants to Tear Things Down': Paul Krugman Explains How Trump's Destructive Tendencies Imperil Us All

President Donald Trump's petulant outbursts at this week's NATO summit showed that his foreign policy is more about acting tough than it is about securing actual benefits for the American people.

This became clear when he — out of the blue — said that member nations should spend 4 percent of their GDP on defense, upping the ante from 2 percent he has emphasized and that other nations had already agreed to. Four percent is, in fact, more than Trump himself has proposed spending on the U.S. defense budget, which is already out-of-control and extremely wasteful.

Tossing out this preposterous figure just reinforced how whimsical and fundamentally meaningless Trump's demands are. This is especially true since Trump is always playing down that threat the Vladimir Putin's Russia poses to the world.

If Putin is so harmless, why is it important that NATO members bolster their defense spending? The blatant contradictions are enough to suggest that Trump has no idea what he's doing.

But in a new column Thursday, economist Paul Krugman argues that Trump does know what he's doing — he's simply trying to destroy.

"Was there anything our allies could have done that would have mollified him?" he writes in the New York Times. "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."

This, Krugman argues, is precisely Trump's strategy in the trade war. He doesn't have concrete or comprehensible demands — he's just aiming to wreak havoc for its own sake. This puts everything from the relative stability of international relations to the global economic system at risk.

He also argues that Trump's ties to Russia also factor into an explanation: "Part of the answer is that anything that weakens the Western alliance helps Vladimir Putin; if Trump isn’t literally a Russian agent, he certainly behaves like one on every possible occasion."

Other actors in U.S. politics could conceivably stop Trump — few have the motivation to cause chaos for the fun of it, as Trump does. But as Krugman sees it, no one is stepping up to the plate:

You might have thought that Congress would place some limits, that there were at least some responsible, patriotic Republican lawmakers left. But there aren’t.

Alternatively, you might have thought that big business, which is deeply invested, literally, in the existing world order would protest effectively. So far, however, it has been utterly ineffectual. And while talk of trade war sometimes causes the stock market to wobble, as far as I can tell, investors still aren’t taking this seriously: They imagine that Trump will bluster and tweet for a while, then accept some cosmetic policy changes and call it a win.

But letting Trump be Trump hasn't worked out well so far. And unless something major changes soon, the situation is likely to get worse.