Donald Trump once celebrated the U.S.-Mexico-Canada Agreement as one of the greatest achievements of his presidency.

He hailed it as a historic replacement for NAFTA. He promised it would protect American workers, strengthen manufacturing and deliver a better future for farmers.

Now, Trump’s administration has declined to renew that very deal in its current form.

The decision does not immediately end the USMCA. Trade under the agreement continues for now. But by refusing to approve a new 16-year extension during the pact’s first major review, the administration triggered a decade-long period of annual reviews and negotiations that could ultimately end with the agreement expiring in 2036.

For critics, the move is a stunning reversal.

The trade agreement was negotiated and signed by Trump during his first term, replacing the North American Free Trade Agreement with a new framework for commerce between the United States, Mexico and Canada. The U.S. Trade Representative’s office has described the USMCA as beneficial for American workers, farmers, ranchers and businesses.

But Trump’s team now says the deal needs to be reshaped.

U.S. Trade Representative Jamieson Greer has argued that the administration wants changes aimed at reducing trade deficits, strengthening American supply chains and tightening rules around manufacturing and regional content. Talks with Mexico are expected to continue, including negotiations over auto rules of origin and other trade issues.

The result is not a clean break.

It is something potentially more unsettling for businesses, farmers and workers who depend on predictable trade rules: years of uncertainty.

Under the agreement’s review mechanism, the United States, Mexico and Canada can still reach a deal at any point during the coming decade to extend the pact. But without that agreement, the USMCA would expire on July 1, 2036.

That uncertainty is already causing alarm among industries that rely on cross-border trade.

The USMCA governs roughly $2 trillion in annual trade across North America. Farm groups and manufacturers have warned that keeping the agreement intact is important for export markets, supply chains and long-term investment. Automakers fear that stricter rules could raise costs, while agricultural groups say open trade with Canada and Mexico remains vital for American farmers.

For former Republican operative Tim Miller, the political contradiction is hard to miss.

Trump is now stepping back from a deal he once portrayed as an unmatched victory.

“The Trump administration decided not to renew the USMCA,” Miller said on The Bulwark podcast. “Which is pretty interesting because Donald Trump said that was the best agreement we’ve ever made, the best trade deal of all time.”

Miller argued that moving toward annual reviews could create a situation in which the future of North American trade is repeatedly reopened — leaving Mexico, Canada, farmers and businesses waiting to see what Trump demands next.

His concern was especially focused on rural America.

“The farmers, it’s one hit after another for the farmers,” Miller said, suggesting that Trump’s policies have repeatedly placed pressure on an important part of his political coalition.

That criticism was echoed by New Yorker writer Susan Glasser, who argued that Trump’s relationship with his most loyal supporters has become defined by a strange political pattern: supporters remain loyal even when policies appear to move against their interests.

“As far as the farmers go, Donald Trump loves to provide evidence that his ride or die supporters will be there no matter how much he humiliates them,” Glasser said.

The White House sees the situation differently.

Administration officials have insisted that they are not abandoning North American trade but seeking a better deal for Americans. The USTR has said its negotiating goals include ensuring that the agreement benefits U.S. manufacturers, farmers, ranchers, workers and service providers.

Mexico and Canada have both signaled they want negotiations to continue. Canada has said it is prepared to work toward improvements, while Mexico has warned that changes should not harm its key industries.

But for the people who make long-term decisions — whether to expand a factory, buy new equipment, hire workers or plant next year’s crop — uncertainty is its own kind of cost.

A trade agreement once marketed as Trump’s triumph is now entering its most unstable chapter.

And for farmers who believed the deal would bring them certainty, the question is becoming painfully simple:

What happens when the president decides his “best ever” deal is no longer good enough?