U.S. Air Force B-52 bombers arrive at Al Udeid Air Base in Qatar

A pair of U.S. Air Force B-52 Stratofortress bombers from Barksdale Air Force Base, Louisiana, taxi after landing at Al Udeid Air Base, Qatar, April 9, 2016. The U.S. Air Force deployed B-52 bombers to Qatar on Saturday to join the fight against Islamic State in Iraq and Syria, the first time they have been based in the Middle East since the end of the Gulf War in 1991. REUTERS/U.S. Air Force/Staff Sgt. Corey Hook/Handout via Reuters THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS