Over the last six months, the United States has left behind the global trade order that persisted for decades in favor of something drastically different and largely untested.

Formidable economies like the European Union and Japan have abruptly made peace with higher tariffs on their exports, acquiescing to President Trump’s demands in order to avoid damaging trade wars and to coax even steeper U.S. duties down just a little bit.

As major economies fall in line to sign agreements that include the highest tariffs in modern history, the president’s vision for global trade is rapidly being realized. That new normal uses America’s economy as leverage, with other countries accepting tariffs of 15 to 20 percent to do business with the United States. Even higher rates will be imposed on exports of critical products, like steel, or on certain adversarial countries, like China.

The outcome has seemingly proved Mr. Trump right that his tariff threats are a powerful bargaining tool. And the muted market reaction to 15 percent tariffs on Japan and the European Union suggests that the panic many expected from his earlier, more extreme levies may not materialize.

Nigel Green, the chief executive of deVere Group, a global financial advisory, called the E.U. deal “a reset, not a resolution.”

“A year ago, markets would have recoiled,” he said. “Today, they’re simply grateful it wasn’t worse.”