A Saudi soldier fires a mortar towards Houthi movement position, at the Saudi border with Yemen April 21, 2015. (Photo by Reuters/Stringer)

Soldiers take part in a drill during a heavy snow in Heihe, Heilongjiang province, February 26, 2014. (Photo by Reuters/China Daily)

A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

Three Chinese soldiers at the time of a civil war in China. (Photo by General Photographic Agency/Getty Images). 1922

These images, scanned from old glass negatives which had surfaced in northern France, were believed to have been taken by a local amateur photographer in 1916. They showed British and a few Australian soldiers, in formal or informal poses, during or just before the most murderous battle in the history of the British Empire – Battle of the Somme. Who are these British and British Empire soldiers? The identity of the soldiers is, and may always remain, a mystery... (Property of Bernard Gardin/Dominique Zanardi/Joel Scribe/The Independent Magazine)

Members of the Communist New Fourth Army on parade. Note how the modern equipment contrasts with the shoeless soldiers in the foreground. (Photo by Hulton Archive/Getty Images). 6th July 1946

North Korean soldiers look at South Korea across the Korean Demilitarized Zone (DMZ), on December 22, 2011 in Panmunjom, South Korea. (Photo by Chung Sung-Jun/Getty Images)

The BADGER shot was a 23 kiloton nuclear bomb. Over 2,000 US soldiers were within 3.7 kilometers of the explosion. (Photo by Alamy Stock Photo)