Nearly everybody’s weighing in on the fate of our vital trade agreement with Canada and Mexico- NAFTA. However, if you think America’s most important trading priority right now is the renegotiation of NAFTA, you might be mistaken.

Something else may be just as critical looking forward: the survival of Trade Promotion Authority (TPA).

NAFTA grabs most of the attention these days. Although talks continued recently in Montreal, President Trump has threatened to quit them entirely. Meanwhile, Prime Minister Justin Trudeau of Canada said last week that he might pull out first because he’s fed up with the lack of progress. Then there’s Mexico, whose presidential election this summer presents a looming political distraction that could slow down the negotiations even more.

Yet we can’t afford to overlook a separate fact: TPA is about to expire. President Trump must ask for its renewal and Congress must approve it.

Failure to accomplish these steps not only would kill NAFTA, including any of the improvements that President Trump has promised, but they’d make it almost impossible for the United States to complete any new trade talks at all.

This means that while most of the countries in the rest of the world will keep on lowering trade barriers and improving the flow of goods and services across borders, Americans would be stuck with the status quo—at least until Washington gets its act together and reauthorizes TPA.

Here are the facts.

Our government’s executive branch negotiates trade pacts with other countries. The president oversees these efforts, relying on the office of the U.S. Trade Representative. In the Trump administration, the trade representative is Robert Lighthizer.

Yet neither President Trump nor USTR Lighthizer can finalize any deals on his own. Instead, the president submits proposed agreements to Congress, which makes the final decision about joining.

This is where Trade Promotion Authority (TPA) comes in. It’s a legislative tool that lets Congress debate a proposed agreement and cast an up-or-down vote. What TPA prevents, however, is tinkering. The up-or-down vote blocks amendments that would force the U.S. Trade Representative to go back to the drawing board with our trading partners.

Without TPA, trade diplomacy would cease. Nothing ever would get done. In fact, nothing ever would start because countries would refuse to negotiate with us, on account of Congress’s power to meddle.

Since the 1970s, every president—both Democrat and Republican—has taken advantage of this legislative device to open foreign markets to American-made products. The original, bipartisan approval of NAFTA also relied on TPA, though back then it was usually called “fast track.”

In 2015, President Obama asked for a three-year continuation of TPA and a Republican-controlled Congress gave it to him—a positive sign of cooperation during an era of growing partisan rancor. President Obama had intended to use TPA for the Trans Pacific Partnership, a prospective agreement involving Pacific Rim nations. Yet the talks dragged on and a year ago, shortly after Obama left office, President Trump abandoned them. The 11 remaining TPP participant countries are still proceeding, but the United States is no longer a partner.

The clock is now ticking on TPA. The extension granted in 2015 will expire this year, on July 1. To ensure uninterrupted coverage, President Trump must formally ask for its extension 90 days beforehand, which means that the real deadline for TPA is April 1. Then Congress will have to decide what to do.

United States Trade Representative Robert Lighthizer (AP Photo/Evan Vucci)

The good news is that USTR Lighthizer has said that the White House intends to seek the renewal of TPA.

The bad news is that the White House hasn’t done this yet—and like a football wide receiver who misses an easy catch because he takes his eyes off the ball, it’s always possible to forget the fundamentals. That’s especially true amid the daily rush of politics, to say nothing of the diversion of a major investigation.

So by all means, let’s keep making the case for NAFTA. I’m hoping that when the talks conclude, we’ll find ourselves with a better arrangement that makes it even smoother for goods and services to flow both ways across our borders with Mexico and Canada.

But let’s also remember that we need TPA (Fast Track)—for without TPA, we won’t even be on the trade track!