NATO conducts massive air drill to test defense against simulated attack.

NATO is set to launch its largest-ever air force deployment in its history in a training scheme intended to stimulate an attack on an allied nation. The drill, dubbed Air Defender 23, will take place over Germany and involve 10,000 participants and 250 aircraft from 25 countries, including 100 aircraft and 2,000 personnel from the U.S. The exercises are meant to ensure a coordinated response from NATO allies under Article 5 of the alliance's charter, which states that an attack on a NATO member nation is considered an attack on all the members.