Gil Barndollar and Rajan Menon, The Guardian »

In threatening war with both Canada and Mexico, Trump is obliterating America’s greatest strategic advantage.

In normal times, one would be hard-pressed to find a pair of friendlier nations than the United States and Canada. Canadians and Americans share a common language (aside from the Québécois), sports leagues, US$683bn in trade, and the world’s longest undefended border, more than 5,000 miles (8,000km) long. Americans and Canadians have fought side by side in both world wars, as well as in Korea and Afghanistan.

Trump’s coveting of Canada is easy to mock and dismiss. Since returning to office in January, he has said repeatedly that he wants to make Canada the 51st state and taken to calling former Canadian prime minister Justin Trudeau “Governor Trudeau.” In what could be a satire of the post-9/11 ambitions of some American neoconservatives, Trump called the border with Canada “an artificial line” that “makes no sense”.

But Canadians aren’t laughing.

Barely three months into his second term, Donald Trump has damaged, perhaps even irrevocably, relationships with his country’s two neighbors and largest trading partners. Few US presidents have committed greater strategic malpractice. None have done it with such speed. If the president wants to identify something he has achieved that none of his modern-day predecessors have, this feat would certainly qualify.