Image 0 of 16Army Spc. Colton Davis fires a Javelin shoulder-fired anti-tank missile during a combined arms live fire exercise as part of Exercise Eastern Action 2019 at Al-Ghalail Range in Qatar, Nov. 14, 2018. The multiple exposure photo demonstrates the multiple stages the missile goes through after it is fired by Davis. (Spc. Jovi Prevot/National Guard) Three Ukrainian naval ships are seen at dock the day after being seized by Russian forces on Sunday, Nov. 25, 2018, in Kerch, Crimea, The Ukrainian parliament is set to consider a presidential request for the introduction of martial law in Ukraine following an incident in which Russian coast guard ships fired on the two Ukrainian navy gunboats and tugboat. (AP Photo) Hill Air Force Bases 388th and 419th fighter wings line up 36, F-35A's on the runway to prepare for take-off on November 19, 2018 in Hill Air Force Base, Utah. This combat training exercise is to help the 388th and 419th, the only combat ready units for the F-35A's, to be ready to launch multiple aircraft on short notice in the defense of the country. (Photo by George Frey/Getty Images) Meharists of the Mauritanian National Guard are seen on November 23, 2018, in Nema, southeast Mauritania, ahead of the National Day. (THOMAS SAMSON/AFP/Getty Images) A Ukraine army APC moves toward on position at an undisclosed location in eastern Ukraine, Monday, Nov. 26, 2018. Ukrainian lawmakers were set to consider a presidential request for the introduction of martial law in the country on Monday following an incident in which Russian coast guard ships fired on Ukrainian navy vessels. (AP Photo/Alexander Shulman) Marines with Weapons Company, 3rd Battalion, 3rd Marine Regiment, maneuver from a chemically gassed area during Exercise Bougainville II at the Pohakuloa Training Area, Hawaii, Oct. 20, 2018. (Sgt. Ricky Gomez/Marine Corps) A U.S. Army light medium tactical vehicle assigned to the 9th Mission Support Command, Army Reserves, Honolulu, is driven on a U.S. Naval Landing Craft Utility operating out of the USS Ashland (LSD 48) during beach-front loading and unloading of vehicles on Saipan, Commonwealth of the Northern Mariana Islands, Nov. 12, 2018, as part of the Super Typhoon Yutu relief effort. (Tech. Sgt. Christopher Ruano/Air Force) Two F-35C Lightning II aircraft attached to the Argonauts of Strike Fighter Squadron (VFA) 147, stationed at Naval Air Station Lemoore, fly in formation for a photo exercise over the California desert on Nov. 16, 2018. (Chief Mass Communication Specialist Shannon E. Renfroe/Navy) A U.S. Air Force F-16 Fighting Falcon assigned to the 36th Fighter Squadron at Osan Air Base, Republic of Korea (ROK), positions to receive fuel midair during a training flight over South Korea in Nov. 19, 2018. (Senior Airman Kelsey Tucker/Air Force) A Ukraine army soldier stands on duty with his heavy machine gun at an undisclosed location in eastern Ukraine, Monday, Nov. 26, 2018. Ukrainian lawmakers were set to consider a presidential request for the introduction of martial law in the country on Monday following an incident in which Russian coast guard ships fired on Ukrainian navy vessels. (AP Photo/Alexander Shulman) Ships with the Ronald Reagan Carrier Strike Group and John C. Stennis Carrier Strike Group transit the Philippine Sea on Nov. 16, 2018, during dual carrier operations. (MC2 Kaila V. Peters/Navy) Army Cpl. Brandon Chadwick, of the New Jersey National Guard, fires the M240 machine gun during weapons training on Joint Base McGuire-Dix-Lakehurst, N.J., Nov. 6, 2018. (Master Sgt. Matt Hecht/Air National Guard) Sailors attached to the U.S. 7th Fleet flagship USS Blue Ridge (LCC 19) prepare turkeys for the ship's Thanksgiving celebration on Nov. 21, 2018, at Yokosuka, Japan. Navy culinary specialists across the fleet are preparing an estimated 112,000 pounds of roast turkey, 21,000 pounds of stuffing, 27,100 pounds of mashed potatoes, 18,500 pounds of sweet potatoes, 5,400 pounds of cranberry sauce, and 2,300 gallons of gravy. (MC3 Dylan McKay/Navy) Soldiers of the Mauritania Army wait in armed vehicles at a G5 Sahel task force outpost in the southeast of Mauritania, along the border with Mali, on November 22, 2018. (THOMAS SAMSON/AFP/Getty Images) A U.S. Marines helicopter flies past a pedestrian bridge after the closing of the United States-Mexico border was ordered on November 25, 2018 at the San Ysidro border crossing point south of San Diego, California. - US officials closed a border crossing in southern California on Sunday after hundreds of migrants tried to breach a border fence from the Mexican city of Tijuana, US authorities announced. The US Customs and Border Protection office in San Diego, California, said on Twitter that it had closed both north and south access to vehicle traffic at the San Ysidro border post, before also suspending pedestrian crossings. (SANDY HUFFAKER/AFP/Getty Images) U.S. Customs and Border Protection (CBP) agents (L) stand watch as U.S. Marines handle concertina wire at the San Ysidro port of entry during a "large-scale operational readiness exercise" which briefly closed the border crossing on November 22, 2018 in Tijuana, Mexico. Parts of the migrant caravan have been arriving to Tijuana after traveling for more than a month through Central America and Mexico to reach the U.S. border. (Photo by Mario Tama/Getty Images)