U.S. Trade Representative Michael Froman speaks as the twelve Trans-Pacific Partnership member countries participate in the closing newsconference in Atlanta on Monday. (Erik S. Lesser/European Pressphoto Agency)

THE UNITED STATES and 11 other nations concluded the long-awaited Trans-Pacific Partnership trade deal, or TPP, on Monday — demonstrating that it is still possible for this country to exercise world leadership, and to do big things in its own national interest, given consistent White House leadership and sufficient bipartisan support in Congress.

As President Obama sees it, the TPP would achieve both economic and strategic goals. By slashing tariffs and harmonizing regulatory regimes covering 40 percent of the global economy, the deal would spur growth in the United States and abroad. By knitting the U.S. and Japanese economies together in their first free-trade deal — and binding both of them closer to rising Asian nations — the TPP would create a counterweight to China in East Asia. Not incidentally, the deal would also help Japan’s prime minister, Shinzo Abe, overcome domestic interest-group resistance to reforming his nation’s sclerotic economy.

Those arguments persuaded bipartisan majorities of the Republican-controlled Congress to empower Mr. Obama’s negotiating team with so-called “fast-track” authority this year, and, as predicted, that vote helped win substantial new access to the Japanese and other markets for U.S. producers, as well as provisions on the environment and labor rights — including Vietnam’s first acceptance of possible independent trade unions.

In granting the administration fast-track authority, Congress rejected claims from a legion of critics to the effect that the TPP would sell out U.S. workers, the environment or even public health. In fact, the tentative deal would ensure that a controversial dispute arbitration system is more transparent and cannot be used by tobacco makers to escape member nations’ tough regulations. The U.S. team also struck a compromise designed to protect the legitimate intellectual property interests of American drugmakers without depriving poor nations of access to life-saving medicine.

It’s good that the critics lost the fast-track debate in Congress; but it’s not bad we had that debate, because it helped U.S. negotiators identify areas of legitimate concern and, accordingly, areas where the deal could incorporate those concerns. What’s emerged from the talks suggests that the TPP will indeed live up to Mr. Obama’s promise of a “21st-century” agreement: one that anchors the United States in a key region for decades to come, while increasing the scope of trade policy beyond just tariffs.

Difficult as it has been to reach this point, the last leg — final passage for the TPP in both houses of Congress during an election year — could prove even more difficult. Republican Donald Trump and Independent-running-as-Democrat Bernie Sanders have been whipping up protectionist sentiment against the TPP even before they knew what would be in it. Over the course of the next few months, the public and Congress will have an opportunity to pore over the pact. If its details prove to be as advertised, people are likely to conclude that the benefits of the deal outweigh its risks. For now, though, it’s enough to note the fact that Washington can still get something done, and to celebrate that.