The NATO alliance is getting a new supreme commander this week, a former top-ranking U.S. military officer in Korea who has been described by Defense Secretary Ash Carter as a proven warrior-diplomat and "a soldiers' general."

U.S. Army Gen. Curtis M. Scaparrotti was installed Tuesday as head of U.S. European Command, and will become NATO's supreme allied commander Europe following a separate ceremony Wednesday at alliance military headquarters in southern Belgium.

Scaparrotti, 60, will become the 18th U.S. officer to hold the post since Gen. Dwight D. Eisenhower became the first NATO SACEUR in 1951. The commander is responsible for the overall direction and conduct of global military operations for the 28-nation NATO alliance, which now faces multiple security challenges ranging from a resurgent Russia to armed Islamic extremism.