Ukraine’s shock drone strike on Russia’s strategic bomber fleet this week has generals and analysts taking a new look at threats to high-value United States aircraft at bases in the homeland and abroad – and the situation is worrisome.

At least three were killed and 49 injured in a missile-and-drone attack that focused on Kyiv, days after a daring assault on Moscow’s bomber fleet.

Drones are “ubiquitous, because they are quite useful, and they're demonstrating that every day in Ukraine,” one analyst told NBC News.