NATO is rushing to buy more ground-based air defense systems as analysts say Europe cannot defend against all drone and missile attacks in a large-scale war.

"You can never protect everything," said Justin Bronk, top airpower expert at the Royal United Services Institute. "It's completely impossible to defend everything." Even well-defended areas "still get hit all the time," Bronk said, adding that "you can't throw enough at air defense to defend everything from everything."

"You've got to make tough choices," said Mick Ryan, former Australian Army Major General. Ryan stated that even with expanded capabilities, Europe "would still need to make really hard choices about what the priorities to protect were."

Drone and missile proliferation is complicating air defense in modern warfare. Even with robust air defense spending, it is impossible to defend all incoming attacks in a large-scale war. Russia's invasion of Ukraine has involved mass drone attacks and missile bombardments.

Ukraine is fielding low-cost drone interceptors at scale to counter Russian drones. Ukrainian companies have developed interceptor drones that soldiers use to down Russian drones at a low cost. Allies are scrambling to buy cheap drone interceptors despite limited supply.

"It's a wicked problem set that's coming home," said Douglas Barrie, air power expert at IISS. "Europe will inevitably have to make difficult choices."

Air defense capacity in the West is deeply insufficient for a large-scale war or a protracted campaign. Ground-based air defense systems take years to produce, face production backlogs, and are expensive.