U.S. soldiers wrestle with South Korean soldiers in a muddy ring during a joint ranger training exercise at a ranger camp near the demilitarised zone (DMZ) June 25 2003 in Paju, South Korea. (Photo by Chung Sung-Jun/Getty Images)

A soldier fires a rocket gun as Ukrainian soldiers in the Donetsk region, where the country's most intense clashes occur, attend intensive combat training by using both domestic and foreign weapons amid Russia-Ukraine war in Donetsk, Ukraine on May 08, 2023. Infantry is always prepared in a conflict where heavy weaponry like aircraft, helicopters, tanks and other heavy armored vehicles, artillery systems, and mortars are widely deployed on frontline. Combat readiness and experience training of the 57th Brigade of the Ukrainian army continues in Donetsk. (Photo by Muhammed Enes Yildirim/Anadolu Agency via Getty Images)

Students of the General Yermolov Cadet School take part in combined military training with members of a local youth military patriotic club at a boot camp of the Russkiye Vityazi (Russian Knights) military patriotic club in the village of Sengileyevskoye outside Stavropol, Russia February 8, 2017. (Photo by Eduard Korniyenko/Reuters)

Israeli soldiers from the mixed-gender Lions of the Jordan battalion, under the Kfir Brigade, check their weapons at the end of the last training before being assigned their posting, on February 28, 2017, near the West Bank village of Bardale, east of Jenin. (Photo by Jack Guez/AFP Photo)

A picture taken on March 16, 2017 shows women dressed up as mermaids posing by a pool at a mermaid training school in Moscow. Russian women who have dreamt of becoming a mermaid since their youngest years, start turning their fantasies into reality with a new type of fitness – mermaid swimming. (Photo by Natalia Kolesnikova/AFP Photo)

A soldier helps another with her ear protection at the Terningmoen Camp in Elverum, Norway on March 23, 2017. Soldiers demonstrate their skills and tactics during a contract drill as they train to become part of the world's first all-female special forces unit, the Jegertroppen or “hunter troops”. (Photo by Carolina Reid/NBC News)

A group of people are seen on a Victoria line train in London, England during the first night of the Night Tube service on August 19 2016. The Central line and Victoria line are the first to operate a Night service with further lines expected to be running by the end of the year. (Photo by SWNS.com)