A Minuteman III missile engine is loaded into a truck for transport to another building for X-raying before being torn down and rebuilt. The Air Force's missile command-and-control structure has been the subject of several recent scandals. Douglas C. Pizac/AP hide caption

itoggle caption Douglas C. Pizac/AP

An Oct. 28, 1985 photo of John A. Walker Jr., being escorted by a federal marshal as he leaves the Montgomery County Detention Center in Rockville, Md., enroute to a federal court in Baltimore. He was ultimately sentenced to life in prison on espionage charges. Bob Daugherty/AP hide caption

itoggle caption Bob Daugherty/AP

This handout photo provided by the Office of the Defense Secretary (OSD), taken Aug. 19, 2014, shows a Chinese fighter jet that the White House said Friday conducted a "dangerous intercept" of a U.S. Navy surveillance and reconnaissance aircraft. Uncredited/AP hide caption

itoggle caption Uncredited/AP

This handout photo provided by the Office of the Defense Secretary (OSD), taken Aug. 19, 2014, shows a Chinese fighter jet that the White House said Friday conducted a "dangerous intercept" of a U.S. Navy surveillance and reconnaissance aircraft. Uncredited/AP hide caption

itoggle caption Uncredited/AP

A U.S. Navy P-8 Poseidon aircraft takes off from Perth International Airport during the search for Malaysia Airlines MH370. The same general type of aircraft was involved in a "dangerous intercept" by a Chinese fighter jet earlier this week off Hainan island. Reuters/Landov hide caption

itoggle caption Reuters/Landov

Vice Adm. Ted Branch, the director of naval intelligence, was one of two top officers to have their access to classified material suspended. /U.S. Navy hide caption

itoggle caption /U.S. Navy

Police say Aaron Alexis, who was killed Monday, gunned down 12 people at the Washington Navy Yard. FBI/Reuters/Landov hide caption

itoggle caption FBI/Reuters/Landov

Aaron Alexis, whom the FBI believes to have been responsible for the shootings at the Washington Navy Yard in Washington, D.C., is shown in this handout photo released by the FBI on Monday. FBI/Reuters/Landov hide caption

itoggle caption FBI/Reuters/Landov

King George VI and Queen Elizabeth arrive at the Washington Navy Yard on June 9, 1939, to join President Franklin Roosevelt on a cruise down the Potomac River to Mount Vernon, Va. AP hide caption

itoggle caption AP