“That is certainly much clearer today than when it was first planned,” Mr. Weil said. “Since the Russian invasion of Ukraine, we know that the European security architecture, as we have assumed it for decades, no longer functions, and that national defense must therefore have a much greater significance.”

At their core, however, the Air Defender drills appear intended to show President Vladimir V. Putin of Russia the risks of pushing NATO too far.

“I’d be very surprised, shall we say, if the alliance wasn’t kind of looking at this as part of its overall messaging strategy,” said Mr. Barrie, the analyst in London.

The American ambassador to Germany, Amy Gutmann, predicted that leaders around the world would most likely be paying attention — and “that includes Mr. Putin.”

Many of the skills that will be tested over the coming days in Germany have been honed by Western pilots and air support crews over the past 20 years, especially in wars in Iraq and Afghanistan, said Col. Rusty Ballard, commander of the Air National Guard’s 182nd Airlift Wing, based in Peoria, Ill.