Canada has formally applied to join the British-led Joint Expeditionary Force, a rapid-response military partnership among 10 North Atlantic NATO members, according to Prime Minister Mark Carney's office. The move comes as Poland warns that Russia is preparing to escalate hybrid attacks against NATO members supporting Ukraine.

Carney's office said the application reflects Canada's effort to diversify its defense relationships beyond the United States. The prime minister's office said Canada has "formally applied to join the Joint Expeditionary Force" and welcomed British support for that bid.

The JEF groups Denmark, Estonia, Finland, Iceland, Latvia, Lithuania, the Netherlands, Norway, Sweden and the United Kingdom alongside Canada in a coalition built around rapid military response. Canada is already a NATO member, but the JEF application signals a push for closer cooperation with European allies specifically, according to Reuters.

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The application follows a meeting between Carney and British Prime Minister Andy Burnham in northern England, where the two discussed defense industrial cooperation through the Global Combat Air Programme, an advanced fighter jet initiative Canada joined as an observer in July 2026.

The timing places Canada's alliance-building alongside a stark warning from Warsaw about the security risks facing NATO's eastern flank. Polish Prime Minister Donald Tusk told parliament on Thursday that Russia is planning hybrid-style drone and missile strikes against nations supporting Ukraine, including Poland itself, as the war reaches what he called its most decisive stage.

Tusk said intelligence gathered by Polish services points to a Kremlin strategy of damaging Ukraine's economy and logistics while testing NATO's resolve through attacks on member states. He described this as the "most likely scenario" currently facing the alliance.

Poland has already experienced a series of suspicious incidents tied to its role as a conduit for aid to Ukraine, including cyberattacks on public utilities such as water and energy infrastructure, and damage to a rail line connecting Warsaw to the Ukrainian border. A Russian missile crashed in eastern Poland in late July, and NATO jets shot down a Russian-origin drone over Lithuania this week, according to Bloomberg.

Tusk warned that any future strike on NATO territory is likely to be framed by Moscow as accidental, a narrative designed to discourage a collective alliance response. He said Ukrainian cities can expect sustained attacks targeting defense-related infrastructure and rail networks in the weeks ahead.

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Taken together, the two developments point to a NATO alliance in flux on two fronts at once: expanding its membership structures to bring in partners like Canada, while bracing for an intensifying campaign of attacks that blur the line between conventional warfare and hybrid tactics against member states themselves. For Canada, formal participation in the JEF puts it inside a coalition explicitly organized around rapid response to exactly the kind of destabilizing incidents Poland says are coming.

Neither Carney's office nor the Polish government indicated a direct link between Canada's application and the threat Tusk described. But the near-simultaneous timing underscores how quickly the security calculus facing NATO's members, new and existing, is shifting.

"There is a real risk that drones or other types of missiles may fly into the territory of one or more NATO countries on the eastern flank," Tusk said.