Breakdown shows Washington now prioritises its own interests over any semblance of shared economic ground

• ‘No more!!!’: Trump lashes out after US-Canada talks devolve into trade war

The calamitous collapse of trade negotiations between Canada and the United States is a warning to nations worldwide that pursuing any kind of dialogue with the current US administration is doomed at the outset, according to observers who say this recent episode indicates seeking a fair deal is futile.

Andrea Lawlor, an associate professor of political science at McMaster University in Ontario, said: “No matter the closeness of the historical relationship, the American administration has signalled that it now prioritises its interests above those of some sort of global economic coordination or harmony.

Treasury secretary Scott Bessent’s attempt to calm bond markets is a sign of weakness not strength

“Look, there’s nothing magic about that $40tn number,” the US Treasury secretary, Scott Bessent, told CNBC insouciantly last week, as the country’s debt mountain surpassed another bleak record.

Yet Bessent’s decision to intervene in government bond markets in an effort to combat soaring yields belied his studied calm in TV interviews – and reignited fears the US may be on the road to a debt crisis.