The significant military strategy during the U.S. military's involvement in the Vietnam War was guerrilla warfare. This unconventional form of combat, employed by the North Vietnamese and Viet Cong, involved small, mobile units engaging in hit-and-run attacks against larger conventional forces. The strategy aimed to undermine U.S. morale and extend the conflict, making it challenging for American forces to achieve clear victories. Guerrilla tactics, combined with the environmental advantage of the dense jungles, posed significant challenges for U.S. troops, ultimately contributing to a growing anti-war sentiment back home.