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)

Canadian soldiers from the Royal 22nd Regiment take up a position during a non-combative extraction operation in a simulated village as part of Rim of the Pacific (RIMPAC) 2016 exercise held at Camp Pendleton, California United States, July 11, 2016. (Photo by Mike Blake/Reuters)

A Russian Rosguardia (National Guard) soldier stands at a central avenue in front of a restaurant promoter, a day before Sunday's protest in St. Petersburg, Russia, Saturday, January 30, 2021. (Photo by Dmitri Lovetsky/AP Photo)

A soldier looks at a line during a ceremony to mark Martyrs' Day at the Tiananmen Square in Beijing, China, 30 September 2022. Martyr's Day is celebrated on the eve of National Day of the People's Republic of China to commemorate the people who sacrificed their lives in pursuit of national independence. (Photo by Mark R. Cristino/EPA/EFE)

Several soldiers from the Spanish Air Force observe a Eurofighter EF-2000 fighter aircraft of the Spanish Air Force, as it flies during the Ocean Sky 2023 Military Exercise for advanced air-to-air training in the southern airspace of the Canary Islands, Spain on October 25, 2023. (Photo by Borja Suarez/Reuters)

This handout picture released by the Israeli army on May 31, 2024 shows Israeli soldiers during operations in the Gaza Strip amid the ongoing conflict between Israel and the Palestinian militant group Hamas. (Photo by Israeli Army/AFP Photo)

Ukrainian soldiers fire with D-30 artillery at Russian positions in the direction of Klishchiivka as the Russia-Ukraine war continues in Donetsk Oblast, Ukraine on August 12, 2023. (Photo by Diego Herrera Carcedo/Anadolu Agency via Getty Images)

Waura Indians wrestle during this year's “quarup”, a ritual held over several days to honour in death a person of great importance to them, in Xingu National Park, Mato Grosso State, Brazil August 25, 2013. (Photo by Ueslei Marcelino/Reuters)