WASHINGTON, DC - JULY 07: U.S. Joint Chiefs of Staff Chairman Gen. Martin Dempsey (R) and U.S. Secretary of Defense Ashton Carter (L) answer questions during a hearing held by the Senate Armed Services Committee July 7, 2015 in Washington, DC. Carter and Dempsey testified on the topic of "Counter-ISIL Strategy." (Photo by Win McNamee/Getty Images)
Soldiers patrol around the wreckage of a suicide car bomber that smashed into pickup truck carrying security officers, on June 24, 2015 in Mogadishu, in the latest in a string of attacks. There was no immediate claim of responsibility, but Somalia's Al-Qaeda linked Shebab carry out regular bombings and attacks in the troubled capital. AFP PHTO/MOHAMED ABDIWAHAB (Photo credit should read Mohamed Abdiwahab/AFP/Getty Images)
LOS ANGELES - AUGUST 5: Los Angeles police officers wearing contamination suits secure the area following the explosion of a "dirty bomb" during a simulated attack at a dock at the Port of Los Angeles on August 5, 2004 in Los Angeles, California. In the drill's scenario, a "dirty bomb" smuggled into the port in a shipping container exploded as a bus was driving by, releasing a plume of radioactivity. More than 850 civilian and military personnel representing more than 60 government agencies, community based and private-sector organizations are participating in the terror response drill, "Determined Promise 2004". (Photo by David McNew/Getty Images)
WASHINGTON, DC - JULY 23: Lt. Gen. Robert Neller takes his seat during his confirmation hearing before the Senate Armed Services Committee July 23, 2015 on Capitol Hill in Washington, DC. Neller, who commanded troops in Iraq from 2005 to 2007, is the Obama Administration's choice to succeed Gen. Joseph Dunford as 37th commandant of the Marine Corps. (Photo by Alex Wong/Getty Images)
WASHINGTON, DC - JULY 15: U.S President Barack Obama speaks during a press conference in the East Room of the White House in response to the Iran Nuclear Deal on July 15, 2015 in Washington, DC. The landmark deal will limit Iran's nuclear program in exchange for relief from international sanctions. The agreement, which comes after almost two years of diplomacy, has also been praised by Iranian President Hassan Rouhani but condemned by Israeli Prime Minister Benjamin Netanyahu. (Photo by Alex Wong/Getty Images)
