SYDNEY--It was rare moment for bipartisanship in Washington and an even rarer coalition that made it happen.  But in seeing through the passage of trade promotion authority (TPA), or “fast-track”, a White House-Congressional Republican alliance bucked intense opposition from organized labor and other advocacy groups, clearing the way to achieve significant new free-trade arrangements for the 21st century.

A neophyte watching Congressional votes over the past week could be excused for assuming President Obama was the leader of the Republican Party, working together to salvage a deal.  An easy mistake to make considering a majority of his actual party on Capitol Hill—and with Democratic presidential contender Hillary Clinton equivocating at best—nearly torpedoed TPA, legislation that had been granted to every post-war president, but Richard Nixon. 

In the end, party affiliation mattered: Last week a vote to back fast track received the support of 190 Republicans and 28 Democrats in the House. This week, the legislation received yeas from 47 Republicans and 13 Democrat senators.

Bismarck’s comparison of law-making to sausage-making—noting that neither make a pretty sight—is most apt here.  But an inside-the-Beltway focus on the legislative acrobatics of the past month overlooks the significance of what has happened.

Yes, it is a win for President Obama and his signature foreign-policy initiative: the so-called pivot, or rebalance, to intensify U.S. attention and resources in the Asia-Pacific.

For much of the Obama era, the conventional wisdom has dismissed the “pivot” as lacking substance. In reality, Washington has deepened its strategic and diplomatic engagement in the region in recent years. It has committed to shifting the current 50-50 balance of forces between the Atlantic and the Pacific to 40-60 in favor of the latter by 2020. And it has enhanced security ties with major long-time allies such as Japan and Australia and created new ones with old foe Vietnam and former colony the Philippines. Meanwhile, the U.S. has sought to check Chinese overreach in the South and East China Seas.

That said, TPA rejection could have doomed the 12-nation Trans-Pacific Partnership (TPP) talks, undermining not only U.S. competitiveness but also the structural reforms of Japanese Prime Minister Shinzo Abe. It could have left an opening for China to pursue its own rules for regional trade and investment, labor conditions, cyber security, intellectual property and environmental protection.

Coming on top of Washington’s clumsy attempts to discourage allies from joining the China-led Asian Infrastructure Investment Bank (AIIB), the repudiation of Washington’s trade agenda would have signaled a diminishing U.S. presence in the region. It would have also turned Mr. Obama into the lamest of lame ducks.

If anything, a more strategically-minded commitment to the TPP and its economic implications was all-too-lacking in much of rebalancing effort.  With this week’s legislation empowering the White House to conclude the TPP, that looks to change.

But even more importantly, in addition to being a win for the pivot, the past week marks a victory for American leadership in framing the long-term strategic and economic future for this dynamic region and beyond.

Since the end of World War II, American leadership in pushing for greater flows of goods, capital, technology and talent has been one of the most powerful engines of economic growth, not just for the United States but across the globe. With the Doha Round of world trade talks at an impasse, it became clear by the mid-2000s that further steps toward a more open trade and investment regime at a global level would need to be built from the ground up, through bilateral and multilateral agreements among like-minded countries.

Hence the decision by the George W. Bush administration in 2008 to become a negotiating partner in the TPP and President Obama’s drive to complete the regional trade pact during his term in office. Mr. Obama in particular sought to link the TPP to a broader strategy to engage and harness the promise of the dynamic Asia-Pacific region.

Successfully moving ahead with TPP partners—which alone account for nearly 40 percent of global GDP—and eventually bringing other major regional economies on board including South Korea, China and Taiwan, will define the economic future of Asia and the world for decades to come—and help assure that future favors American and allied interests.  That is a strategic outcome that will resonate long after this president’s departure from Washington.

To be sure, there is much work ahead to get the TPP done and convince Congress it is done right and ready for ratification.  No small tasks.

Still, President Obama and his unlikely Republican allies can justly celebrate a victory, and not only for the pivot and economic opportunity. Along with other Americans and their supporters across the region they can also celebrate the prospect of a more confident, reliable and engaged America in the Pacific century.

Bates Gill is chief executive of the United States Studies Centre at the University of Sydney where Tom Switzer is editor of American Review.