Trump’s prices come up against reality while the economic strategy vacillates

After weeks of boastful and climbing, President Trump blinked. Then he blinked. And again.

He fell off his threat to dismiss the president of the federal reserve. Its secretary of the treasury, extremely aware that the S&P 500 was down 10% since Mr. Trump was inaugurated, reported that he was looking for an offramp to avoid an intensive trade war with China.

And now Trump has recognized that 145% tariffs on Chinese products he announced only two weeks ago are not durable. He was partially invited by the warnings of senior executives from Target and Walmart and other large American retailers that consumers would see price overvoltages and empty shelves for certain products imported in a few weeks.

Mr. Trump’s meeting with reality consisted of a living case study in the political and economic costs of the hardest shot of harsh lines. He entered this trade war by imagining a simpler era in which imposing punistent prices would force companies around the world to build factories in the United States.

It ends the month to discover that the world of modern supply chains is much more complex than it has negotiated and that it is far from clear that its “beautiful” prices will have the effects it predicted.

It is not, of course, the explanation of the events of the last days that the White House extinguishes. Mr. Trump’s assistants insist that his maximalist requests were an act of strategic brilliance, forcing 90 countries to align to deal with the president. This can take months, they recognize, to see the resulting dealerships. But to fold the global trade system with American Will, they say, take time.

“Have a certain patience and you will see,” the President’s press secretary, Karoline Leavitt, told journalists on Wednesday.