Ukrainian service man Oleksandr of 24th brigade stands guard at his position in the trenches at the frontline, amid Russia?s attack on Ukraine near Niu York, Donetsk region, Ukraine on April 4, 2023. (Photo by Kai Pfaffenbach/Reuters)

Female Afghan National Police (ANP) officers aim their weapons during a drill at a training centre near the German Bundeswehr army camp Marmal in Mazar-e-Sharif, northern Afghanistan on December 11, 2012. (Photo by Fabrizio Bensch/Reuters/File Photo)

Men are held by Iraqi national security agents, to be interrogated at a checkpoint, as oil fields burn in Qayara, south of Mosul, Iraq, Saturday, November 5, 2016. Islamic State fighters launch counterattacks in the thin strip of territory Iraqi special forces have recaptured in eastern Mosul, highlighting the challenges ahead as the battle moves into more densely populated neighborhoods where coalition air power must be used more selectively. (Photo by Felipe Dana/AP Photo)

Relatives of Ukrainian photographer Maksim Levin, killed while covering Russia's attack on Ukraine, react during his funeral in the town of Boiarka, outside of Kyiv, Ukraine on April 4, 2022. (Photo by Valentyn Ogirenko/Reuters)

In this September 19, 2014 photo, explosives are detonate by Peruvian counternarcotics forces on a part of a clandestine grassy airstrip in the Apurimac, Ene and Mantaro River Valleys, or VRAEM, the world's No. 1 coca-growing region, in Ayacucho, Peru. The dynamiting of craters by Peruvian security forces into clandestine airstrips cuts into profits but hardly discourages cocaine traffickers who net tens of thousands of dollars with each flight flown from these airstrips. (Photo by Rodrigo Abd/AP Photo)

Natalia Arango works with her mine detector in a zone of landmines planted by rebels groups near Sonson in Antioquia province, November 19, 2015. Women's work takes on a nontraditional meaning for fifteen Colombian women who work to rid the Antioquia Mountains of deadly landmines as the country edges closer to a peace agreement with Marxist rebels to end over a decade of conflict which has claimed 220,000 lives. (Photo by Fredy Builes/Reuters)

Rescuers pull dead whales ashore in Probolinggo, East Java, Indonesia, Thursday, June 16, 2016 during a mass rescue operation of stranded whales. Most of more than 30 stranded whales were managed to be pulled into the deep sea, an official said. (AP Photo/Trisnadi)

The Vietnam Slide Project was created by photo editor Kendra Rennick, who began collecting photo slides after a close friend lost her father, a Vietnam veteran. Her friend found a box of slides that her father had taken while in Vietnam and from there Rennick has continued to collect photographs that Vietnam veterans took during their tours of duty. Here: A photo taken from the collection of D.Thornton, who served in the First Air Cavalry division of the United States Army. (Photo by D.Thornton/The Vietnam Slide Project)