Trump’s Tariffs Are the Highest in a Century. But After His Threats, They Seem Like a Relief.

Six months ago, few people would have anticipated that the United States would place a 15 percent tariff on exports from Japan, one of America’s closest and most longstanding allies. President Trump had campaigned on the idea of a 10 percent universal base-line tariff, plus a higher levy on China, but it was not clear whether he would follow through.

But on Tuesday, when Mr. Trump announced a trade deal that included a 15 percent tariff on Japanese products — the highest rate those goods have faced in decades — there was a palpable sense of relief. Stock markets in Asia and Europe rose. The Japanese Nikkei 225 surged by over 3.5 percent, while shares of Japanese automakers, which will also be charged a 15 percent tariff on their exports to the United States, jumped more than 10 percent.

The reaction is a testament to just how quickly and completely Mr. Trump has transformed the world’s expectations regarding tariffs. In a few short months, the president has normalized tariffs at rates that would have been shocking just months ago. But by threatening even higher levies and holding out the prospect of devastating trade wars, he has somehow made sharply higher tariffs, which are now at rates not seen in a century, feel like a relief.

The reaction is largely due to the incredible uncertainty the president has created with his global trade negotiations. He has threatened higher tariffs on dozens of countries as of Aug. 1, unless they strike a deal with the United States. So far, the administration has announced deals with Britain, Vietnam, Indonesia and the Philippines, all of which have left tariffs of 10 to 20 percent in place.

The fact that the United States closed the deal with Japan on Tuesday was in itself a positive surprise. Negotiations between the countries had been difficult, in part because Japan had been heading toward a national election where politicians were under pressure not to fold to the United States on Japan’s core interests.

The governments were also clashing over the 25 percent tariff that Mr. Trump had imposed on global autos, a key export for Japan, as well as Japan’s barriers to U.S. rice, which it has long deemed to be of inferior quality. It was unclear whether the two countries would be able to overcome such barriers.

The key to clinching the deal appeared to be the president’s agreement to lower auto tariffs for Japanese cars to 15 percent. That is significantly lower than the tariff rates that cars from other countries will face, but still a huge increase from the 2.5 percent tariff in effect before Mr. Trump came into office.

Michal Jozwiak, a market analyst at Ebury, a global financial services firm, said the deal was “a potential lifeline for Japan, as it represents a fairly significant concession from the Trump administration, while protecting the country’s vital automotive sector from harsher tariffs.”

It remains to be seen whether the president will offer similar tariffs to other auto exporters. But South Korea, the European Union and Mexico, all of which are in active negotiations, seem likely to push for lower tariffs as part of their own deals.

The Japan deal reinforced “the perception that the White House is open to compromise,” Mr. Jozwiak said.

But while Mr. Trump is celebrating putting his plan into practice and stock markets are at all-time highs, economists have continued to insist that the higher tariffs will eventually start to weigh on the U.S. economy. Price increases have been slow to materialize but started to become more apparent in appliances, toys, furniture and other imported items last month. Economists anticipate that higher prices will weigh on company sales and consumer activity, resulting in slower growth for the U.S. economy.

Ryan Young, a senior economist at the Competitive Enterprise Institute, a libertarian think tank, called the deal a “lose-lose” for both Japan and the United States, saying it would lead to a sevenfold increase on the tariffs Americans are paying on Japanese products.

“While this is a smaller tax hike than President Trump’s threatened 25 percent tariff, it is still a big loss for American consumers and retailers, as well as American manufacturers who use Japanese components,” he said.

Matt Gertken, the chief geopolitical strategist at BCA Research, said there was “little question that Japan would make concessions and come to a deal.” That is because the United States consumes 20 percent of Japanese exports and 37 percent of its car exports. The United States also receives about 43 percent of Japan’s outward direct investment, and also ensures Japan’s national defense, he said.

“Japan can stomach this cost to retain access to the U.S. market,” he added.

In a note to clients on Wednesday, analysts at Nomura said they were revising their forecasts, since recent tariffs had been more aggressive than expected. Mr. Trump’s tariffs on other countries seemed to be settling around 20 percent on average, rather than 10 percent, they said. And the 50 percent tariff the president has placed on foreign steel and intends to place on copper imports was also higher than expected.

The analysts said they now expect the average effective U.S. tariff rate to settle around 19.5 percent, potentially pushing up inflation and weighing on economic growth.

Many foreign governments have come to realize that tariffs will be permanently higher under Mr. Trump, and are just trying to push them as low as possible. It has also been important for other nations not just to have a lower rate overall, but to have a lower tariff than the countries they compete with for American consumers.

For Japan, a 15 percent car tariff is a hefty burden compared with domestic automakers that do not pay tariffs. But it will give Japanese automakers an immediate advantage over car companies in other countries that pay a 25 percent rate.

Patrick Anderson, the chief executive of Anderson Economic Group, an automotive consulting firm, said that the 15 percent tariff on Japanese cars would “put heavy pressure on Germany, Korea and the E.U.” The 25 percent tariff could add costs of $15,000 or more to a luxury car from those countries, he said.

“That’s a punitive amount, and as a result imports of some of these vehicles have effectively halted,” he said.