Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Revellers dressed in mock military garb take part in the “Els Enfarinats” battle in the southeastern Spanish town of Ibi on December 28, 2017. During this 200-year-old traditional festival participants known as Els Enfarinats (those covered in flour) dress in military clothes and stage a mock coup d'etat as they battle using flour, eggs and firecrackers outside the town hall as part of the celebrations of the Day of the Innocents. (Photo by Jaime Reina/AFP Photo)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

Models Felicia Verna and Crystal Boyd wearing Stacey Angela during the Fallen Hearts Fashion Experience at Symphony Space on May 31, 2011 in New York City. (Photo by Jemal Countess/Getty Images)

A model showcases designs on the catwalk by Manning Cartell during A Review of Australian Fashion Week show as part of Mercedes Benz Fashion Festival Sydney 2011 at Sydney Town Hall on August 27, 2011 in Sydney, Australia. (Photo by Don Arnold/Getty Images)

Comedian Jeffrey Ross (C) arrives at Comedy Central's Roast of Charlie Sheen held at Sony Studios on September 10, 2011 in Los Angeles, California. (Photo by Christopher Polk/Getty Images)

A sheep, painted in the colours of World Cup participating country England looks on on September 11, 2011 in Dunedin, New Zealand. (Photo by David Rogers/Getty Images)