Pilots plan a flight manoeuvre with model aircraft at a military air base in Vasylkiv, Ukraine, August 3, 2016. (Photo by Gleb Garanich/Reuters)

Iranian Arabs who are members of the paramilitary Basij force march in a military parade marking the 35th anniversary of Iraq's 1980 invasion of Iran, in front of the shrine of late revolutionary founder Ayatollah Khomeini, just outside Tehran, Iran, Tuesday, September 22, 2015. (Photo by Vahid Salemi/AP Photo)

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)

A Japanese Ground Self-Defense Force Type 92 Mine sweeping vehicle fires a rocket behind a Type 74 armoured tank during an annual training session, which is based on a scenario to defend or retake islands in Japanese territory, near Mount Fuji at Higashifuji training field in Gotemba, west of Tokyo, August 18, 2015. (Photo by Yuya Shino/Reuters)

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)

Nopparat (R), a 24-year-old transgender, and a Buddhist monk (L) wait to speak to officers during an army draft held at a school in Bang Na in Bangkok April 3, 2015. Thai men over 21 must serve in the army. Those who volunteer serve six months, but others choose the annual lottery, which goes on for 10 days in recruitment centres around Thailand. Only those not considered physically capable of service, the mentally ill and those who have significantly altered their physical appearance, such as transgenders, are exempt. Picture taken April 3, 2015. (Photo by Athit Perawongmetha/Reuters)

A U.S. Air Force B-1B Lancer bomber sits on the runway at Anderson Air Force Base, Guam July 18, 2017. (Photo by Airman 1st Class Christopher Quail/Reuters/U.S. Air Force)

Iraqi security forces vehicles take part in a military parade in the streets of Baghdad, Iraq July 12, 2016. Social media activists posted images of tanks, armored vehicles, cannons, soldiers, police officers, and PMF members in Saadoun Street. The photos spiked a rumor of military coup. Military and security advisor and expert Lt. Diyaa al-Wakil said that it is only normal for such rumors to spread since there were no prior announcements about the training. (Photo by Khalid al Mousily/Reuters)