Donald Trump had a plan. It was not a good plan, or even a plausible one. But it was, at least, a coherent plan: By imposing large trade barriers on the entire world, he would create an incentive for American business to manufacture and grow all the goods the country previously imported.

Whatever chance this plan had to succeed is already over.

The key to making it work was to convince businesses that the new arrangement is durable. Nobody is going to invest in building new factories in the United States to create goods that until last week could be imported more cheaply unless they’re certain that the tariffs making the domestic version more competitive will stay in place. (They’re probably not going to do it anyway, in part because they don’t know who will be president in four years, but the point is that confidence in durable tariffs is a necessary condition.)

But not everybody got the idea. Eric Trump tweeted, “I wouldn’t want to be the last country that tries to negotiate a trade deal with @realDonaldTrump. The first to negotiate will win - the last will absolutely lose.”

Eric’s father apparently didn’t get the memo either. Asked by reporters whether he planned to negotiate the tariff rates, the president said, “The tariffs give us great power to negotiate. They always have.”

Someone seems to have then told Trump that this stance would paralyze business investment, because he reversed course immediately, writing on Truth Social, “TO THE MANY INVESTORS COMING INTO THE UNITED STATES AND INVESTING MASSIVE AMOUNTS OF MONEY, MY POLICIES WILL NEVER CHANGE.”

However, there is a principle at work here called “No backsies.” Once you’ve said you might negotiate the tariffs, nobody is going to believe you when you change your mind and say you’ll never negotiate.