Due to political considerations in the United States, no effort was made to block the Ho Chi Minh trail using ground forces. Extensive efforts at air attack did not prevent the North Vietnamese from moving hundreds of tons per day of war supplies down the Ho Chi Minh trail to the south.
On November 11, 1968 Operation Commando Hunt was initiated. The goal of the operation was to interdict men and supplies on the Ho Chi Minh Trail, through Laos into South Vietnam. By the end of the operation, 3 million tons of bombs were dropped on Laos, which slowed but did not seriously disrupt trail operations.
See also Vietnam war guerrilla warfare