A vehicle runs down the 19 km road-and-rail Crimean Bridge passing over the Kerch Strait and linking southern Russia to the Crimean peninsula on May 15, 2018, in Kerch, prior to the opening ceremony. ALEXANDER NEMENOV/AFP/Getty Images
The Pentagon's innovation arm, the Defense Innovation Unit, is helping to modernize the Combined Air Operations Center at Al Udeid Air Base in Qatar, which provides command and control of air power throughout Iraq, Syria, Afghanistan, and 17 other countries. (Tech. Sgt. Joshua Strang/U.S. Air Force)
Air Force Chief of Staff Gen. David Goldfein and Commander of the Colombian Air Force General Carlos Eduardo Bueno salute during a ceremony at the Memorial Heroes Caidos en Combate in Bogotá on Nov. 15. (U.S. Air Force photo by Tech Sgt. Anthony Nelson Jr.)
U.S. Secretary of Defense James Mattis speaks during a press briefing at the Pentagon August 28, 2018 in Arlington, VA. (Photo by Zach Gibson/Getty Images)
U.S. Secretary of Defense Jim Mattis (center) speaks alongside Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford (center left) and other senior Defense Department leaders as he holds a meeting with Indonesia Defense Minister Ryamizard Ryacudu at the Pentagon in Arlington, Virginia, on Aug. 28. (Saul Loeb/AFP/Getty Images)
A Yemeni child suffering from severe malnutrition is weighed at a treatment centre in a hospital in Yemen's northwestern Hajjah province, on November 7, 2018. ESSA AHMED/AFP/Getty Images
A protester demonstrates against the war in Yemen and the killing of journalist Jamal Khashoggi outside the Saudi Embassy in London on Oct. 25. (Jack Taylor/Getty Images)
Democratic candidate Elaine Luria speaks to a room full of supporters after upsetting incumbent Republican Scott Taylor to win Virginia's 2nd Congressional District in Virginia Beach on Nov. 6. (Stephen M. Katz/The Virginian-Pilot via AP)
From left: Mikie Sherrill (D), candidate in New Jersey’s 11th Congressional District; Amy McGrath (D), candidate in Kentucky’s 6th District; Gina Ortiz Jones (D), candidate in Texas’s 23rd District; Elaine Luria (D), candidate in Virginia’s 2nd District; and Martha McSally (R), running for Senate from Arizona. (Mary Altaffer/AP/Alex Wong/Getty Images/Thomas McKinless/CQ Roll Call/Getty Images/Bill Clark/CQ Roll Call/U.S. Air Force/Foreign Policy illustration)
Poll workers help voters at polling station during early voting for the mid-term elections in the Lakeview Terrace neighborhood of Los Angeles, California on November 4, 2018. ROBYN BECK/AFP/Getty Images
From left: Robert Story Karem, assistant secretary of defense for international security affairs, Thomas Goffus, deputy assistant secretary of defense for Europe and NATO, and
Alan Patterson, deputy assistant secretary of defense for African affairs. (William Pratt/U.S. Army/Department of Defense/Foreign Policy illustration)
