A member of the 332nd Expeditionary Security Forces Squadron looks over his shoulder while guarding an entrance point during an active-shooter exercise June 8, 2017, in Southwest Asia. The purpose of the exercise was to evaluate the squadron’s ability to respond to an emergency and improve tactics in a simulated environment. (U.S. Air Force photo/Senior Airman Damon Kasberg)

Pilots assigned to the 60th Air Mobility Wing out of Travis Air Force Base, Calif. fly a KC-10 Extender during a training mission June 21, 2017. The C-17 is capable of rapid strategic delivery of troops and all types of cargo to main operating bases or directly to forward bases in the deployment area. The aircraft can perform tactical airlift and airdrop missions and can transport litters and ambulatory patients during aeromedical evacuations when required. The inherent flexibility and performance of the C-17 force improve the ability of the total airlift system to fulfill the worldwide air mobility requirements of the U.S. (U.S. Air Force photo/Staff Sgt. Andrew Lee)

Staff Sgt. Victoria Dames, a 35th Security Forces Squadron military working dog handler, carries MWD Elvis during the second annual security forces advanced combat skills assessment at Andersen Air Force Base, Guam, June 6, 2017. The Defenders Challenge provided Airmen with invaluable interaction with other security forces members by exchanging tactics and skills between those in attendance. (U.S. Air Force photo/Airman 1st Class Gerald R. Willis)

A Japan Air Self-Defense Force civil engineer airman tries on an M50 gas mask during a bilateral exchange event at Misawa Air Base, Japan, June 21, 2017. Building friendships and enhancing mutual understanding were also vital pieces in this Pacific unity event. After long days of training, U.S. and Japanese CE airmen put on civilian clothes and hosted informal dinners to promote international partnerships. (U.S. Air Force photo/Senior Airman Deana Heitzman)

Senior Airman Joseph Goebel, left, and Airman 1st Class Anthony Ohara, both 35th Operations Support Squadron weather forecasters, analyze climate patterns during Red Flag-Alaska 17-2 at Eielson Air Force Base, Alaska, June 16, 2017. Goebel and Ohara were in charge of running the weather flight for RF-A, which consisted of seven other Air National Guardsman from Joint Base Lewis-McChord, Wash. (U.S. Air Force photo/Airman 1st Class Sadie Colbert)

An F-15E Strike Eagle fires flares during a flight in support of Operation Inherent Resolve June 21, 2017. The F-15E, a component of U.S. Air Forces Central Command, supports U.S. and coalition forces working to liberate territory and people under the control of the Islamic State of Iraq and Syria. (U.S. Air Force photo/Staff Sgt. Trevor T. McBride)

A KC-135 Stratotanker pilot, assigned to the 340th Expeditionary Air Refueling Squadron, looks out an aircraft window before a flight in support of Operation Inherent Resolve at Al Udeid Air Base, Qatar, June 26, 2017. The KC-135 provides aerial refueling capabilities to U.S. and coalition forces working to liberate territory and people under the control of the Islamic State of Iraq and Syria. (U.S. Air Force photo/Staff Sgt. Michael Battles)

Senior Airman Matise Venett, a 5th Aircraft Maintenance Squadron weapons load crew member, inspects munitions before they are loaded into a B-52H Stratofortress at Minot Air Force Base, N.D., June 19, 2017. The training munitions were loaded into an aircraft by the 5th AMXS Global Strike Challenge team during their bomb-loading competition. (U.S. Air Force photo/Senior Airman J.T. Armstrong)

Senior Airman Ryan Green, a combat broadcaster, fires at his target while Tech. Sgt. Samuel Weaver, weapons and tactics training instructor, both assigned to the 1st Combat Camera Squadron, observes his hits during weapons and tactics training on the shooting range at Fort Jackson, S.C., June 22, 2017. The Airmen of the 1st Combat Camera Squadron constantly train for readiness to document combat operations, exercises and other contingencies from the ground and in the air. (U.S. Air Force photo/Tech. Sgt. Larry E. Reid Jr.)

Tactical control party Airmen from the 227th Air Support Operations Squadron descend from a 1-150th Assault Helicopter Battalion UH-60 Black Hawk helicopter during joint training for New Jersey Task Force One at Joint Base McGuire-Dix-Lakehurst, N.J., June 28, 2017. The primary mission of New Jersey Task Force One is to provide advanced technical search and rescue capabilities to victims trapped or entombed in structurally collapsed buildings. Task Force One is made up of New Jersey National Guard Soldiers and Airmen, as well as civilians. (U.S. Air National Guard photo/Master Sgt. Matt Hecht)

Staff Sgt. Eric Jeffcoat, a 100th Security Forces Squadron base defense operation center controller, emerges from smoke grenade smoke during the 435th SFS’s Ground Combat Readiness Training Center Security Operations Course at U.S. Army Garrison Baumholder, Germany, June 15, 2017. Conducting missions as a team and being evaluated by the 435th SFS instructor cadre, students showcased knowledge of urban operations, close quarters combat, live firing iterations, mounted and dismounted patrols, entry control point operations, and counter improved-explosive device operations while at Baumholder. (U.S. Air Force photo/Airman 1st Class Savannah L. Waters)

Airman 1st Class Hogan Lambeth, an 11th Civil Engineer Squadron structural apprentice, welds a metal rod at Joint Base Andrews, Md., June 21, 2017. As a metals structural technician, Lambeth is called on to complete welding, sheet metal, duct work, fabrication and repairs to maintain equipment and facilities throughout the base. (U.S. Air Force photo/Senior Airman Delano Scott)