Open this photo in gallery:

U.S. Undersecretary of Defense for Policy Elbridge Colby attends a meeting at the NATO headquarters in Brussels in February.Geert Vanden Wijngaert/The Associated Press

A senior Trump administration official is publicly criticizing the idea of a collective “middle powers” strategy among American allies and partners, warning it is a “distraction” that could cost them “time, money and political capital.”

In a series of posts on X on Tuesday, Elbridge Colby, the U.S. Undersecretary of Defence for Policy, also pushed back on the idea that allies might turn their back on purchases of U.S. military equipment.

“There is a lot of commentary that, due to alleged frustrations with the United States, the American defense industrial base will lose out on the market for weaponry. But this is neither feasible nor accurate,” Mr. Colby said.

“The United States, as the President says, makes the best equipment, and we make it at a scale that no plausible competitor can match.”

Opinion: Canada is not a middle power – it’s a future great power

If anything, he added, access to the U.S. defence industrial base “is a privilege, not a right.”

Mr. Colby’s posts did not name any countries. But the phrase “middle powers” has become closely associated with Prime Minister Mark Carney, who used it in a blunt January speech to the World Economic Forum in Davos – one widely seen as placing the blame on Donald Trump for what he called a rupture in the rules-based international order.

Mr. Carney said at Davos that middle powers must stop pretending the rules-based order is still functioning, and instead build coalitions to survive in a new era where great powers prey on smaller countries to take what they want.

The Prime Minister has repeatedly talked in the last year of reducing reliance on U.S. military equipment and turning instead to allies in Europe, among others. “The days of our military sending 70 cents of every dollar to the United States are over,” he said as recently as April.

“There is a great deal of hubbub about a collective ‘middle powers’ strategy these days,” Mr. Colby wrote.

He said the Pentagon is “not concerned that this is a serious possibility,” but worried “a few allies and partners will think it is” and pursue this “distraction.” Mr. Colby said he thinks a middle-powers strategy is “based on a faulty understanding of international relations” and argued that no bloc of allied states has “a coherent basis for alignment.”

Mr. Colby described the Trump administration as “flexible realists” who view the world through the lens of “interest, geography, economics, military power, etc.”

He also disputed the idea that allied countries are turning away from the United States under Mr. Trump, saying he sees “an upsurge in desire for engagement” with Washington rather than a reduction.

Mr. Colby said no competitor can match the U.S. defence-industrial base “either in quantity or quality,” and there is “no credible free world alternative to American tech” for defence purposes. He added that allied countries should still increase their own defence spending and build up their own industrial capacity, but in ways “collaborative with America’s rather than trying in vain to replicate or supplant it.”

Fen Hampson, a professor of international affairs at Carleton University, said Mr. Colby’s outburst is an example of what he calls the United States’ “current bipolar disorder,” where Washington under Mr. Trump has become unreliable for allies but still demands deference and attention.

Opinion: As middle powers forge a future without the U.S., Canada walks a tricky path

He characterized U.S. foreign policy right now as “‘We want to cut you loose, but we don’t want you to cut us loose.’”

The bottom line, Prof. Hampson said, is that the Trump administration can’t have it both ways. “You can’t say to your NATO allies, ‘You’re on your own,’ and then complain when they go out on their own.”

In May, Mr. Carney announced Canada had entered into negotiations to buy Swedish-made Saab early-warning aircraft technology, picking a non-U.S. supplier as he made good on a promise to reduce spending on American military gear.

Friction between Canada and the United States over buying U.S. military gear has been growing over the past 12 months. The Trump administration has repeatedly complained about Canada’s decision to pause its order of U.S. fighter aircraft.

Canada under Mr. Carney is also considering whether to scale back its order of 88 U.S.-made F-35 fighters and instead purchase Saab Gripen aircraft.

Follow related authors and topics

Authors and topics you follow will be added to your personal news feed in Following.

Interact with The Globe