An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)

A soldier eats ice cream as she visits a zoo in Pyongyang, North Korea, September 12, 2018. (Photo by Danish Siddiqui/Reuters)

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

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)

Personal possessions of 2004 tsunami victims are arranged to be photographed outside a police station in Takua Pa, in Phang Nga province December 19, 2014. Thai police opened a shipping container filled with documents and possessions of victims of the 2004 Indian Ocean Tsunami after being asked by Reuters for permission to film its contents. The three metre by 12 metre container was handed over to Thai police in 2011 and contains hundreds of plastic police evidence bags – each one holding the precious items found on the body of a victim. (Photo by Damir Sagolj/Reuters)

Yasothon resident look on as huge, handmade rockets are launched into the air during the Bun Bang Fai festival on May 11, 2014 in Yasothon, Thailand. During the Bun Bang Fai rocket festival, Thai residents launch enormous home-made rockets into the air to gain Buddhist merit and to celebrate the beginning of the rainy season. (Photo by Taylor Weidman/Getty Images)

A girl joins other novice nuns for a lunch at the Sathira-Dhammasathan Buddhist meditation centre in Bangkok April 21, 2013. A group of Thai girls are choosing to spend part of their school holidays as Buddhist nuns, down to having their heads shaven at the meditation centre. The centre, founded in 1987, is a learning community for peace and harmony that has programs open to people regardless of age and gender. (Photo by Damir Sagolj/Reuters)

Elephants enjoy various kinds of fruits and vegetables during an all-you-can-eat elephant buffet held to mark the National Elephant Day at the ancient historical city of Ayutthaya, Thailand, 13 March 2014. The annual National Thai Elephant Day is held on 13 March to celebrate and drawing public attention for more concerted effort to save the species and protect its habitat. Thailand sees a severe decline with less than 3,000 wild elephants left in the kingdom. (Photo by Rungroj Yongrit/EPA)