In February 1971, South Vietnamese ground troops undertook a significant military operation by invading Laos, targeting the extensive Ho Chi Minh Trail. This trail was vital for North Vietnam, facilitating the movement of troops and supplies into South Vietnam. The operation, termed Lam Son 719, was executed with the support of U.S. airpower and was aimed at disrupting the logistical support for communist forces, thereby safeguarding South Vietnamese territory. This incursion occurred against a backdrop of dwindling American ground presence as U.S. forces were in the process of withdrawing from the region.

The operation commenced with the involvement of thousands of South Vietnamese soldiers and was designed to establish control over areas of the Ho Chi Minh Trail and to counteract increasing North Vietnamese military activities. Engaging in fierce confrontations, South Vietnamese troops made initial gains but faced stiff resistance from entrenched North Vietnamese forces. The difficulties encountered, including difficult terrain and coordinated counterattacks, led to significant casualties for South Vietnam and highlighted the challenges of conducting military operations in foreign territory without robust ground support from U.S. forces.

Although Lam Son 719 successfully disrupted enemy movements temporarily, the long-term impact was questionable. Critics argued it highlighted the limitations of South Vietnam's military capacity and questioned the effectiveness of U.S. involvement. The operation ultimately prompted a reevaluation of military strategy among South Vietnamese leadership, emphasizing the need for improved capabilities to maintain autonomy in face of continuing threats from North Vietnam.