An air deployment exercise billed as the biggest in NATO’s history and hosted by Germany got underway on Monday. The Air Defender 2023 exercise that is set to run through June 23 was long-planned but serves to showcase the alliance’s capabilities amid high tensions with Russia.

The first planes took off on Monday morning from airfields in northern Germany. Some 10,000 participants and 250 aircraft from 25 nations will respond to a simulated attack on a NATO member. The US alone is sending 2,000 US Air National Guard personnel and about 100 aircraft.