Soldiers of Ukraine's National Guard 1st brigade Bureviy (Hurricane) fire a recoilless cannon during combat training at a military training ground in the north of Ukraine Friday, November 3, 2023. (Photo by Efrem Lukatsky/AP Photo)

A Ukrainian serviceman of 80th Separate Galician Air Assault Brigade makes a snow angel in a bomb crater, amid Russia's attack on Ukraine, at a position near Bakhmut in Donetsk region, Ukraine on January 25, 2024. (Photo by Inna Varenytsia/Reuters)

A serviceman of the Carpathian Sich Battalion is seen at his position on a frontline, as Russia's attack on Ukraine continues, near the town of Lyman, Donetsk region, Ukraine on December 8, 2022. (Photo by Viacheslav Ratynskyi/Reuters)

A Ukrainian serviceman walks an empty street in the front line city of Bakhmut, in Donetsk region, Ukraine on February 25, 2023. (Photo by Serhii Nuzhnenko/Radio Free Europe/Radio Liberty)

A U.S. Army crew chief flying on board a CH-47F Chinook helicopter observes the successful test of flares during a training flight in Afghanistan, March 14, 2018. (Photo by Tech. Sgt. Gregory Brook/Reuters/U.S. Air Force)

Crowds cheer during a parade before the 23rd annual Wing Bowl at the Wells Fargo Center in Philadelphia, Pennsylvania January 30, 2015. Professional competitive eater from Chicago Patrick “Deep Dish” Bertoletti downed 444 chicken wings in 30 minutes at the 23rd annual Wing Bowl in Philadelphia, narrowly edging out his nearest rival and shattering the record of 363 wings set a year earlier. (Photo by Mark Makela/Reuters)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

A young YPJ recruit (in pink) arrives to the training base for her first day in training near Derek City, Syria. The YPJ schedule is demanding and requires discipline – new soldiers in training get about 6 hours of sleep a night and wake up at 4 AM to begin exercising; afterwards, their day consists of a full schedule of drills and classroom lessons. Before joining the YPJ many of the girls had never participated in physical activity or sports before. (Photo by Erin Trieb/NBC News)