Guerrilla warfare involves small, surprise attacks rather than direct confrontation. The Vietcong effectively used guerrilla tactics against American forces during the Vietnam War. They operated from an extensive underground tunnel system to hide and launch ambushes. Though outgunned, the Vietcong's hit-and-run attacks allowed them to inflict heavy casualties while minimizing their own losses. Constantly moving and hiding in tunnels also made them difficult for Americans to track. Overall, guerrilla warfare gave the Vietcong a significant strategic advantage over the better equipped but more conventionally fighting US military.