In this Oct. 24, 2018, photo released by the U.S. Air Force, members of the 7th Reconnaissance Squadron prepare to launch an RQ-4 Global Hawk at Naval Air Station Sigonella, Italy. Iran's Revolutionary Guard shot down a U.S. RQ-4 Global Hawk on Thursday, June 20, 2019, amid heightened tensions between Tehran and Washington over its collapsing nuclear deal with world powers, American and Iranian officials said, though they disputed the circumstances of the incident. (Staff Sgt. Ramon A. Adelan/U.S. Air Force via AP)