Soldiers stand in line outside portable toilets during a military parade to celebrate the 206th anniversary of Colombia's independence in Bogota, Colombia, July 20, 2016. (Photo by John Vizcaino/Reuters)

A Viet Cong suspect holds his hands up after a Vietnamese Ranger from the 21st Vietnam Infantry Division routed him from his hiding place. (Photo by Keystone/Getty Images). 7th November 1967

Devotees offer prayers before taking a holy bath during the Swasthani Bratakatha festival in the Triveni River in Panauti near Kathmandu January 24, 2015. During the month long festival, devotees recite one chapter of a Hindu tale daily from the 31-chapter sacred Swasthani Brata Katha book that is dedicated to the God Madhavnarayan and the Goddess Swasthani, alongside various other gods and goddess and the miraculous feats performed by them. The devotees also go on pilgrimages to various temples, perform religious rituals, take a holy bath in the rivers and fast for a month, especially among women who believe fasting helps in their family's well-being or in getting them a good husband. (Photo by Navesh Chitrakar/Reuters)

A man carries floats as he walks on an algae covered beach as a truck collecting algae passes by, along the coastline in Qingdao, Shandong province, July 6, 2015. (Photo by Reuters/China Daily)

A US Army M1A2 SEP tank participates in the Strong Europe Tank Challenge 2017 at the military training area in Grafenwoehr, Germany, 12 May 2017. Six North Atlantic Treaty Organization (NATO) nations and partner nations, Austria, France, Germany, Poland, Ukraine and the USA are taking part in this competing exercise. (Photo by Christian Bruna/EPA)

Pro-Russian rebels stand near a monument during a ceremony to honour the World War Two defenders of Donetsk from Nazi forces, in Donetsk, in this September 8, 2014 file photo. (Photo by Marko Djurica/Reuters)

The body of one of several U.S. soldiers who were executed after being captured by North Korean troops just south of Seoul in early July 1950. (Photo by AP Photo)

Masooma Alizada (L) and Frozan Rasooli (R), members of Afghanistan's Women's National Cycling Team prepare a bicycle before training on the outskirts of Kabul February 20, 2015. Afghanistan's Women's National Cycling Team has been breaking new ground for women's sports and pushing the boundaries of what is – and is not – acceptable for young women in the conservative Muslim country. (Photo by Mohammad Ismail/Reuters)