It’s like a fistfight between conjoined twins: The United States and Canada are throwing tariffs and insults at each other tit-for-tat in one of the most unnecessary trade wars in recent memory.

“I don’t want Canadian cars. I don’t want Canadian parts. I don’t want Canadian anything,” President Donald Trump posted Sunday, before comparing the tariffs on Canada to his administration’s war against Iran.

But while Trump and Canadian Prime Minister Mark Carney try to check each other into the boards, China is skating free — scoring economic goals at will and choking out North American manufacturing.

And instead of facing Beijing’s economic threat, we’re busy taxing hockey sticks.

Not all hockey sticks, of course — only the wooden ones still made in Canada, which will now face a 50% tariff when shipped to the US.

The trouble is, almost no one uses wooden hockey sticks anymore.

Only one Canadian factory even makes them, shipping a modest 100,000 sticks to nostalgic American beer-league dads.

The composite, carbon fiber sticks that people actually use may have Canadian names on them, but almost all are made in China (small numbers are made elsewhere in Asia).

Those Chinese sticks only face a 20% tariff — a giveaway to the Chinese Communist Party.

Americans and Canadians disagree on plenty — bacon, beer, the names of major bodies of water.

But three decades of booming trade and close cooperation with the Canucks has built an integrated economy so closely tied together that we refer to it as “co-production.”

Take Ford’s heavy-duty F-350 and F-450 truck series: The engine is built in Ontario, but its transmission comes from Ohio and its axles arrive from Michigan.

Or consider the striker plate, a small metal part on your car door that allows it to latch closed — it crosses the US-Canada border four times before final installation.

And that’s just one auto part.

The average car has around 30,000 parts, and most of them crisscross back and forth between Canada, the United States and Mexico on their way to final assembly.

Killing off North American integration will cause real pain at home: lost jobs and lower profits on both sides of the border, higher prices for American cars and other products, and diminished investment as manufacturers pause plans for new plants amid the uncertainty.

Our pain, however, is China’s gain.

As we pursue a sibling scrap, Beijing keeps flooding our markets with replacement goods.

So instead of developing a joint defense against Chinese dumping, the US and Canadian tariffs are making Chinese products even more cost competitive.

Worse, the ongoing spat is pushing a dependable teammate toward America’s chief global rival, as Carney — elected in 2025 in part because of these simmering tensions — is opening the door to Beijing.

Carney visited China in January and came home with a deal for importing Chinese cars and exporting Canadian canola.

Previously, Ottawa had matched Washington’s 100% tariff on Chinese electric vehicles.

The US market matters to Canada: The bulk of its exports, 72%, head to the United States.

But Canada also matters to the US, sending large amounts of oil and gas south — a core aspect of Trump’s energy-independence strategy.

The US also imports 85 to 90% of its potash from Canada, a key ingredient to the fertilizer that American farmers rely on.

And Trump admitted this week that the United States “desperately” needs Canadian aluminum: “We don’t have it. We get it all from Canada for the most part, and we need it badly.”

Backup suppliers of aluminum include Russia and China — bad options for America.

Most important, America and Canada are stuck with one another — literally.

Sharing the world’s longest land border with a friendly country is great for business.

Making an economic enemy along 5,525 miles of open border because of a dispute over hockey sticks and ice cream would be a catastrophic own-goal.

The United States is the strongest country in the world — but North America, as a continent, can be even stronger, providing co-production power and abundant resources that no one on earth could challenge.

North America has the talent, resources and muscle to dominate the ice.

The only question is whether Washington and Ottawa can stop brawling with each other and start playing on the same team.

Josh Birenbaum is deputy director of the Center on Economic and Financial Power at the Foundation for Defense of Democracies, where Susan Soh is a research associate.