Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

A military enthusiast dressed as World War Two Red Army officer sits in a cafe as he marks the 75th anniversary of the Nazi Germany invasion, in Brest, Belarus June 21, 2016. (Photo by Vasily Fedosenko/Reuters)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

A general view of the Burj Khalifa on February 23, 2012 in Dubai, United Arab Emirates. At 829.84 m (2723 ft) tall the Burj Khalifa is currently the tallest building in the world. (Photo by Chris Jackson/Getty Images)

A Palestinian demonstrator (R) shouts at an Israeli soldier, during clashes with Israeli troops at the Qalandiya checkpoint, on June 5, 2011 between Jerusalem and the West Bank city of Ramallah. The clashes come on the 44th Anniversary of the Arab defeat in the 1967 Six Day War of the Middle East. (Photo by David Vaaknin /Getty Images)

Then U.S. Army First Lieutenant Kirsten Griest (C) and fellow soldiers participate in combatives training during the Ranger Course on Fort Benning, Georgia, in this handout photograph taken on April 20, 2015 and obtained on August 20, 2015. When Griest and another woman completed the daunting U.S. Army Ranger school this week they helped end questions about whether women can serve as combat leaders, as the Pentagon is poised to open new roles, including elite Navy SEALs, to women in coming months. The feat by Griest and First Lieutenant Shaye Haver followed a re-evaluation of the role of women after their frontline involvement in Iraq and Afghanistan and the end of a rule barring them from combat roles in 2013. (Photo by Spc. Nikayla Shodeen/Reuters/U.S. Army)

A National Army of Colombia soldier, who was wounded by a mine, swims at a pool in Bello, municipality of Antioquia, March 25, 2015. (Photo by Fredy Builes/Reuters)

Members of the Russian Red Army Choir perform at Water Front Theatre in Beirut September 13, 2014. (Photo by Jamal Saidi/Reuters)