Germany is preparing to host the biggest air deployment exercise in NATO’s history, a show of force intended to impress allies and potential adversaries such as Russia, German and American officials said Wednesday.

The Air Defender 23 exercise starting next week will see 10,000 participants and 250 aircraft from 25 nations respond to a simulated attack on a NATO member country. The United States alone is sending 2,000 U.S. Air National Guard personnel and about 100 aircraft to take part in the June 12-23 training maneuvers.

“This is an exercise that would be absolutely impressive to anybody who’s watching, and we don’t make anybody watch it,” U.S. Ambassador to Germany Amy Gutmann said.

“It will demonstrate beyond a shadow of a doubt the agility and the swiftness of our allied force in NATO as a first responder,” she told reporters in Berlin.

“I would be pretty surprised if any world leader was not taking note of what this shows in terms of the spirit of this alliance, which means the strength of this alliance,” Gutmann said.

“And that includes Mr. Putin,” she added, referring to Russian President Vladimir Putin.

While the drill was planned for several years, Russia’s invasion of Ukraine in February 2022 ear has jolted NATO into preparing in earnest for the possibility of an attack on its territory. Sweden, which is hoping to join the alliance, and Japan are also taking part in the exercise.

“We are showing that NATO territory is our red line, that we are prepared to defend every centimeter of this territory,” said Lt. Gen. Ingo Gerhartz of the German air force, which is coordinating the exercise. “But we won’t, for example, conduct any flights toward Kalinigrad. So this is intended to be defensive.”

Kalinigrad is a Russian exclave located on the Baltic Sea between Poland and Lithuania.

Lt. Gen. Michael A. Loh, director of the U.S. Air National Guard, said the exercise goes beyond deterrence.

“It’s about the readiness of our force. It’s about coordination, not just within NATO, but with our other allies and partners outside of NATO,” he said.

Loh said the exercise would be an opportunity for younger U.S. airmen, many of whom have mainly gotten experience serving in the Middle East, to build relationships with allies in Europe and prepare for a different military scenario.

“So this is about now establishing what it means to go against a great power, in a great power competition,” he said.

Authorities have said the drill will cause some disruption to civilian flights in Europe during the period.

(AP)