France and Germany’s recent agreement to develop a new multibillion-dollar battlefield tank together was immediately hailed by the German defense minister, Boris Pistorius, as a “breakthrough” achievement.

“It is a historic moment,” he said.

His gushing was understandable. For seven years, political infighting, industrial rivalry and neglect had pooled like molasses around the project to build a next-generation tank, known as the Main Combat Ground System.

Russia’s invasion of Ukraine more than two years ago jolted Europe out of complacency about military spending. After defense budgets were cut in the decades that followed the Soviet Union’s collapse, the war has reignited Europe’s efforts to build up its own military production capacity and near-empty arsenals.

But the challenges that face Europe are about more than just money. Daunting political and logistical hurdles stand in the way of a more coordinated and efficient military machine. And they threaten to seriously hobble any rapid strengthening of Europe’s defense capabilities — even as tensions between Russia and its neighbors ratchet up.

“Europe has 27 military industrial complexes, not just one,” said Max Bergmann, a program director at the Center for Strategic and International Studies in Washington.

The North Atlantic Treaty Organization, which will celebrate its 75th anniversary this summer, still sets the overall defense strategy and spending goals for Europe, but it doesn’t control the equipment procurement process. Each NATO member has its own defense establishment, culture, priorities and favored companies, and each government retains final say on what to buy.