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)
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 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)
A Ukrainian MSLR BM-21 “Grad” fires towards Russian positions, near Bakhmut at the frontline in Donetsk region, Ukraine, Wednesday, June 21, 2023. (Photo by Iryna Rybakova via AP Photo)
A member of the Siberian Battalion of the Ukraine's Armed Forces International Legion smokes a disposable vape during military exercises, amid Russia's attack on Ukraine, at an undisclosed location in Kyiv region, Ukraine on December 13, 2023. (Photo by Valentyn Ogirenko/Reuters)
Ukrainian servicemen of the 28th Separate Mechanised Brigade fires a 122mm mortar towards Russian positions at the front line, near Bakhmut, Donetsk region, Ukraine, Sunday, March 3, 2024. (Photo by Efrem Lukatsky/AP Photo)
A Ukrainian Army liaison officer Vira, 22, plays with her rat Malyi (Tiny) at her positions near a frontline, in Donetsk region, Ukraine, on March 8, 2024. (Photo by Inna Varenytsia/Reuters)
Ukrainian soldiers from the assault brigade inflict fire damage with a 120 mm mortar while supporting the assault operations of the infantry on April 19, 2024 in Ukraine. The country's Prime Minister Denys Shmyhal has warned its allies that if more military aid for Ukraine is not approved soon, such as the long-stalled aid package from the United States, it could usher in a “Third World War”. (Photo by Kostiantyn Liberov/Libkos/Getty Images)