The U.S. needs a few good allies. Does it still need Canada?

There's a brief, delicious little vignette at the beginning of military historian Tim Cook's latest book that neatly captures the essence of Canada's decades-long national security and defence relationship with the United States.

Speaking in Kingston, Ont. with Prime Minister William Lyon Mackenzie King at his side, President Franklin D. Roosevelt declared that "the people of the United States would not stand idly by if domination of Canadian soil is threatened by any other Empire."

King — who obviously didn't know what the president was going to say ahead of time — was apparently gobsmacked by the assurance, Cook wrote in The Good Allies: How Canada and the United States Fought Together to Defeat Fascism During the Second World War.

Roosevelt's promise, made on Aug. 8, 1938 in the face of rising fascism in Germany, Italy and Japan, has formed the political bedrock of Canada's national security ever since — much to the delight (and chagrin) of Canada's political establishment down the decades.

At the time, King apparently saw the remark for what it was — a historic declaration from a like-minded democracy. He also understood the unspoken aspect.

"It was also a threat of sorts; that the United States would trample Canadian sovereignty if it saw a foreign menace north of the border," Cook wrote.

In 2024, that aspect of Roosevelt's remarks has lost much of its menace. It has been replaced with what former top Canadian national security officials often describe as a deepening sense of exasperation and frustration in Washington with the shiftless attitude in Ottawa that the pledge seems to have created.

Cook documents in his book, often in vivid detail, the genesis of the Canada-U.S. security relationship — lately dominated by American grumbling over Canada's reluctance to hit NATO's military spending benchmark of two per cent of gross domestic product.

His analysis is particularly instructive when you consider the strains on that relationship today, and the persistent sniping of U.S. lawmakers from both sides of the aisle.

When the U.S. needed Canada

As the world once again watches the rise of authoritarian dictatorships, the United States appears to be once again searching for a few good allies. That may be why the exclusion of Canada from the high-tech submarine deal involving Australia, the United States and the United Kingdom still stings so much in Ottawa.

The Second World War was "one of the few times when the United States understood it needed Canada," Cook told CBC News. Canada's geography, mineral wealth and (at the time) untapped industrial potential made it a natural defence partner for the U.S.

Cook suggests that complacency set in on both sides of the border in the decades since, and particularly since the end of the Cold War. Canada's political and institutional establishments have benefited from the American security umbrella, allowing this country to invest generously in social development.

But on the flip side, the United States has had to think about security on its northern border the way it has in the southern region.

"One of the things I have found in reading hundreds of books and documents is that Canada barely registers in any of these discussions in the United States about security issues," Cook said.

"Canada was a very good ally to the United States [during the Second World War], acknowledged at the time, and perhaps we've been too good in that alliance."

If there has been a persistent policy failure (or perhaps a political character flaw) on Canada's part, it could be its apparent inability to tell its story in Washington.

"If we were to talk about today, perhaps we need to shout a little louder about our own accomplishments and to talk about security and defence," said Cook.

At last summer's NATO Summit in Washington, Canada's Ambassador to the United States Kirsten Hillman was careful to emphasize the lengths Canadian diplomats go to in order to get attention in the U.S. capital.

She insisted that the Canada-U.S. relationship is as strong as ever, particularly on security and defence.

"We are sophisticated countries with many policies that we're seeking to develop and many ways in which to contribute, not only our homeland security, but the security of our world,"  Hillman said in response to a reporter's questions in July.

"The conversations are not one-note. They're complicated. They're serious. And we are taken very seriously."

Vincent Rigby, a former national security and intelligence adviser to the prime minister, agreed with Cook that Canada is often under-appreciated in Washington and inconsistent in how it presents its message to the Americans.

Promises, promises

"The challenge, I think, especially currently, is that you don't want to go down to Washington if you don't have a good story to tell, or if you just have a series of niggling little asks," Rigby told CBC News.

In a recent policy paper, Rigby argued that Canada's reputation with the United States is at its lowest point since Roosevelt extended the security umbrella almost nine decades ago.

Much of it, he said, is related to successive Canadian governments making promises on defence and either not following through on them or taking a ponderously long time to deliver.

"It's difficult to engage the Americans," said Rigby, now a professor at the Max Bell School of Public Policy at McGill University. "We've lost their trust, I think, and we are not particularly credible allies."

It's not a question of the U.S. saying jump and Canada asking how high, Rigby added. It's not even merely a matter of fulfilling our obligations as members of NATO and NORAD. It's about understanding the lesson of 1938, he said — what the Americans were looking for then and now.

"The U.S. ... when it comes right down to it, looks through virtually everything in a bilateral relationship through a national security lens, or a defence lens, no matter what the issue is," Rigby said. "And if you are not stepping up in terms of national security and defence, it is going to impact other parts of the relationship."

Roosevelt was a Democrat, of course. Rigby said there's another lesson Canadians ought to learn from his example: Democrats are no more likely than Republicans to overlook it when Canada fails to meet its defence commitments.

"If we get into this world where we think this is all about [Donald] Trump, and that if Trump and the Republicans do not gain power in the next election that we're going to be okay and we're going to get a free pass, we are sorely, sorely mistaken," he said.

"The world is going to get worse before it gets better … So Canada, what can you do for us? I think it's going to come from a [Kamala] Harris administration, if she wins the election. And I think you're going to see it become a little bit blunter and a little bit more strident."