Secretary of Defense Jim Mattis meets with troops stationed at Al Udeid Air Base, Qatar, April 21, 2017, during his tour of Africa and the Middle East. The purpose of his trip is to reaffirm key U.S. military alliances, engage with strategic partners and discuss cooperative efforts to counter destbilizing activities and defeat extremist organizations. (DOD photo by U.S. Air Force Tech. Sgt. Brigitte N. Brantley)