United States Marine Corps Staff Sgt. Jason Itro yells at recruit Nancy Carbins January 15, 2003 after she grabbed another recruit in the pool in an attempt to stay afloat during swim training at the Combat Pool on Parris Island, SC. Under the watchful eyes of swim instructors, recruits are required to swim in full gear and learn limited strokes and breathing to stay afloat. Carbins broke a major rule by grabbing another recruit and submerging them both. (Photo by Stephen Morton/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 Cuban migrant couple rests inside a tent at a provisional shelter in Paso Conoa, at the border with Costa Rica March 20, 2016. More than 1,500 Cuban immigrants are waiting at Costa Rica's southern border with Panama as they seek overland passage towards the United States, according to local officials. (Photo by Carlos Jasso/Reuters)

In this photo made Thursday, April 11, 2013, Soviet Jewish World War Two veteran Boris Ginsburg poses for a portrait at his house in the southern Israeli city of Ashdod. Ginsburg, born in Belorussia, was kept by a German garrison in the Lenin ghetto since 1941 until its destruction by partisan units in September 1942. In 1942 he joined the partisans for two years and in 1944 he joined the Red Army as a combat soldier and fought till the and of the war. Ginsubrg demobilized in 1947 and immigrated to Israel in 2001. About 500,000 Soviet Jews served in the Red Army during World War Two, and the majority of those still alive today live in Israel. (Photo by Oded Balilty/AP Photo)

This stirring collection of photos which offer a glimpse behind the scenes of army life have all been selected as winners in an annual competition. The remarkable pictures in the Army Photographic Competition show Britain's soldiers at work and play. They have been taken by amateur and professional soldier cameramen and include images from operations in Afghanistan, air shows and sporting events. The winners were announced at a ceremony held at the Army Headquarters in Andover in Hampshire. (Photo by Jamie Peters/MoD/Geoff Robinson Photography/REX Features)

An Iraqi soldier drives MRAP at his base in Makhmour, after it was freed from control of Islamic State, south of Mosul, April 17, 2016. (Photo by Ahmed Jadallah/Reuters)

Participants dressed as characters such as elves, dwarves, goblins and orcs from the J.R.R. Tolkien's novel “The Hobbit” re-enact the “Battle of Five Armies” in a forest near the town of Doksy, Czech Republic, June 4, 2016. Several hundred people arrived in the forest to re-enact the famous battle from Tolkien's novel that was published for the first time in 1937. (Photo by David W. Cerny/Reuters)