WASHINGTON — A simmering trade dispute between the United States and Canada has escalated into a full-blown nuclear crisis after Ottawa signaled it could cut off exports of uranium — a move that would directly threaten the fuel supply for America’s fleet of nuclear power reactors and force the Trump administration into a confrontation it had sought to avoid.

The warning, delivered through quiet diplomatic channels over the weekend, has sent shockwaves through Washington. According to multiple sources familiar with the discussions, Canadian officials made clear that uranium exports could be restricted if the Trump administration proceeds with threatened tariffs on Canadian energy products — a line that, if crossed, would transform a trade dispute into a direct threat to the American energy grid.

President Trump erupted upon being briefed on the Canadian warning, according to aides who spoke on condition of anonymity. The former president, who has made energy dominance a central theme of his political identity, was said to be “apoplectic” that a country he has long characterized as dependent on the United States could wield such leverage over American infrastructure.

But in Ottawa, the response has been unflinching. Prime Minister Mark Carney’s government has framed the dispute as a matter of sovereign底线, with officials noting that Canada is under no obligation to supply a critical resource to a country that has repeatedly threatened its economic security.

“The United States has treated our resources as if they are American resources by right,” a senior Canadian official said, speaking on condition of anonymity to discuss sensitive deliberations. “They are not. And if the choice is between supplying a hostile trading partner or protecting our own interests, the answer is clear.”

The numbers behind the threat are stark. Canada supplies approximately 22 percent of the uranium used in American nuclear power reactors — a figure that insiders say changed the tone of the entire conversation overnight when it was presented to White House officials. Unlike other minerals where the United States has alternatives, uranium presents a unique vulnerability.

Nuclear power accounts for nearly 20 percent of America’s electricity generation, with 94 operating reactors across 28 states. The fuel cycle is complex and highly regulated; unlike oil or natural gas, uranium cannot be quickly sourced from alternative suppliers without years of lead time and extensive safety certifications.

American uranium mining has declined precipitously over the past decade, with domestic production accounting for less than 5 percent of U.S. reactor needs. The remainder is imported, with Canada and Kazakhstan as the primary suppliers. A disruption from Canada would leave American utilities scrambling to fill a gap that cannot be easily closed.

“The uranium supply chain is not like a gas station where you can just pull in from a different supplier,” said Edward McGinnis, a former senior Energy Department official who oversaw nuclear fuel security. “Every batch has to be certified, tested, and approved for each specific reactor. Disrupting that supply would create immediate operational challenges and long-term uncertainty.”

The Canadian warning represents a significant escalation in a trade conflict that has already seen Ottawa redirect Arctic minerals toward Europe and Asia, effectively excluding the United States from access to rare earths, lithium, and cobalt. But uranium cuts into something far more sensitive: the steady operation of America’s baseload power supply.

Behind the scenes, key advisors are reportedly weighing scenarios where supply disruptions could ripple across energy systems faster than expected. The Nuclear Regulatory Commission has been quietly reviewing contingency plans, while utility executives have begun privately lobbying the White House to de-escalate the dispute.

“We are watching this with extreme concern,” said Maria Korsnick, president of the Nuclear Energy Institute, the industry’s trade association. “The nuclear fleet operates on just-in-time fuel delivery. Any disruption to the supply chain would be felt immediately, and the consequences would cascade across regional power grids.”

The uranium standoff traces its origins to the same trade tensions that have roiled the U.S.-Canada relationship for months. The Trump administration has threatened tariffs on Canadian energy imports, including electricity, natural gas, and refined petroleum products. Canadian officials have consistently warned that such measures would be met with retaliation — and have now signaled that uranium is in their sights.

What makes the uranium threat particularly potent is the absence of easy alternatives. American utilities have spent decades integrating Canadian uranium into their fuel cycles. Switching to Kazakh or Australian sources would require requalification, new contracts, and in some cases, reactor modifications. Even in a best-case scenario, the transition would take years.

For states with significant nuclear generation — including Illinois, Pennsylvania, South Carolina, and Virginia — the implications are immediate and deeply political. Republican senators from these states have quietly urged the administration to reconsider its tariff posture, warning that constituents would not forgive energy disruptions born of trade fights.

The White House has so far maintained a defiant tone. Trump, in a series of social media posts, called Canada’s threat “economic blackmail” and vowed that the United States would not be “held hostage by a foreign power.” But the absence of a clear countermeasure has exposed the administration’s vulnerability on an issue where leverage is asymmetrical.

Ottawa, meanwhile, isn’t blinking. Officials are framing the dispute as a line that won’t be crossed, even as pressure builds behind closed doors on both sides of the border. The Canadian uranium industry, concentrated in Saskatchewan’s Athabasca Basin, is the world’s largest high-grade uranium producer — and it has markets elsewhere.

“Canada has other customers,” said the senior Canadian official. “Europe is expanding its nuclear fleet. Asia is building reactors at an unprecedented rate. The United States has made clear it does not value our partnership. We will sell to those who do.”

As the standoff continues, the nuclear industry is bracing for what could become the most serious energy crisis since the 1970s oil embargoes. The number that changed everything — 22 percent — now hangs over every conversation. And in Washington, the question is no longer whether Canada will use its leverage. It is how much damage the United States is willing to absorb before it blinks.