How successful were they?
The United States conducted two major campaigns to search and destroy the tunnel system: Operation Crimp (1966) and Operation Cedar Falls (1967). Operation Crimp hoped to target a key Viet Cong headquarter location believed to be unground. Significant causalities ensued on both sides, but the combined Australian and American forces were unable to fully uncover the extensive tunnel network. Similarly, Operation Ceder Falls attempts to uncover and destroy the tunnel system. This attempt enjoyed more success than Crimp but was short-lived as the tunnels were in working order again within weeks.
Overall, the Vietnamese were very quick to restore damages and continue as if nothing happened. This restoration was pivotal as it enabled some of the key successes enjoyed by the Viet Cong. Mai Chi Tho, brother of Le Duc Tho (a prominent Hanoi Politburo member) highlights how they used the tunnels to infiltrate Saigon. Tho claims the Viet Cong prepared both the necessary troops and assembled the supplies needed in these tunnels to conduct the Tet Offensive of 1968. This offensive is commonly seen by historians as a turning point for American involvement in the Vietnam war.
In hindsight, listening to the Viet Cong talk about their experiences in these tunnels, it appears more training certainly would have benefitted the American cause. One Viet Cong soldier highlighted their lack of discreteness. Tunnel rat soldiers often used flashlights to guide the way and thus warned the enemy of their presence. In fact, volunteers boasted of their ability to change flashlights in pitch black without realizing the damaging consequences of this. Similarly, one American soldier highlighted how they liked to ‘soften things up’ by throwing in one or more hand grenades before sending in tunnel rats. However, as the Viet Cong soldier highlighted, by throwing grenades into the void ahead, or shooting pistols, the noise was deafening and alerted them to their presence.
Needless to say, sadly many of those Americans who did enter the tunnels ended up dying. The exact figure, however, remains unknown as there were no extensive records kept on this exact type of engagement with the enemy. According to archives held by the US government, there were 58,220 US military deaths overall as a result of the Vietnam War. The War also claimed the lives of approximately 200,000 allied soldiers in Vietnam, nearly one million North Vietnamese/ Communist allied deaths, and an incomprehensible number of civilians.