U.S. Air Force Gen. John Hyten, commander of U.S. Strategic Command (USSTRATCOM), welcomes Deputy Secretary of Defense Patrick Shanahan upon his arrival at USSTRATCOM headquarters, Offutt Air Force Base, Neb., April 19, 2018. During his visit, Shanahan met with USSTRATCOM leadership to discuss nuclear command and control processes and 21st century strategic deterrence. This was Shanahan’s first visit to USSTRATCOM as deputy secretary of defense. One of nine Department of Defense unified combatant commands, USSTRATCOM has global missions assigned through the Unified Command Plan that include strategic deterrence, space operations, cyberspace operations, joint electronic warfare, global strike, missile defense, intelligence, and analysis and targeting.