Today’s headline about Poland calling on NATO to invoke Article 4 is a reminder of how fragile Europe’s security environment has become. Article 4 is not Article 5—it doesn’t mean automatic collective defense—but it does mean that a member state feels threatened enough to request urgent consultations. Poland, sharing a long border with both Ukraine and Belarus, is on the frontline of Europe’s current tensions.

The question, though, is bigger than Poland. It’s whether NATO, and Europe more broadly, can afford the political, economic, and military weight of a new war.

On the surface, NATO has overwhelming military superiority compared to any potential adversary. The problem is not capability—it’s sustainability. Europe is already in a period of economic strain. Rising energy costs, inflationary pressures, fragmented supply chains, and political instability have left the EU weaker than it was even five years ago. Public frustration over stagnant growth and immigration challenges has fueled populism, making consensus harder to build within the alliance.

At the same time, U.S. attention is split. Washington still carries the bulk of NATO’s military burden, but its strategic gaze is increasingly locked on Asia. That leaves European nations needing to step up. Poland has been one of the few to seriously ramp up defense spending, but countries like Germany, France, and Italy face internal divisions over how much sacrifice is acceptable.

So, can NATO afford a war? Militarily, yes. Politically and economically, the answer is far less clear. A conflict on NATO’s eastern flank would test not only the alliance’s unity but the resilience of Europe’s fragile economies. And in democracies where public opinion matters, prolonged hardship could erode support faster than tanks can be built or troops mobilized.

In other words, NATO has the means to fight—but whether it has the will to endure is the real question.