[For an even deeper look at what’s on Paul Krugman’s mind, sign up for his weekly newsletter.]

Remember, Trump’s two signature economic policies were his 2017 tax cut and his rapidly escalating trade war with China. The first was supposed to lead to a decade or more of rapid economic growth, while the second was supposed to revive U.S. manufacturing.

In reality, however, the tax cut delivered at most a couple of quarters of higher growth. More specifically, huge tax breaks for corporations haven’t delivered the promised surge in wages and business investment; instead, corporations used the windfall to buy back stocks and pay higher dividends.

At the same time, the trade war has turned out to be a major drag on the economy — bigger than many people, myself included, expected. Until last fall the general expectation was that Trump would deal with China the way he dealt with Mexico: make a few mainly cosmetic changes to existing arrangements, claim victory, and move on. Once it became clear that he was really serious about confrontation, however, business confidence began falling, dragging investment down with it.

And voters have noticed: Trump’s approval rating on the economy, while still higher than his overall approval, has started to decline. Hence the panicky demands that the Fed pull out all the stops.

But while Trump realizes that he’s in trouble, there’s no indication that he understands why. He’s not the kind of person who ever admits, even to himself, that he made mistakes; his instinct is always to blame someone else while doubling down on his failed policies.

Even actions that look like a slight policy softening, like his announcement of a two-week delay in implementing some China tariffs, betray a deep incomprehension of the problem — which has as much to do with his capriciousness as with the tariffs per se. Policy zigzags, even if they involve delaying tariffs, just add to the will-he-or-won’t-he uncertainty that’s causing companies to put investment on hold.

So what happens next? Trump could reverse course, and do what most people expected a year ago, reaching a deal with China that more or less restores the status quo. But that would be a de facto admission of defeat — and at this point it’s not clear why the Chinese would trust him to honor any such deal past Election Day. The fact is that when it comes to economic policy, Trump has trapped himself in a bad place.

The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. And here’s our email: letters@nytimes.com.

Follow The New York Times Opinion section on Facebook, Twitter (@NYTopinion) and Instagram.