 Westmoreland adopted a strategy of attrition against the Viet Cong and the North Vietnamese Army, attempting to drain them of manpower and supplies.He also made use of the United States' edge in artillery and air power, both in tactical confrontations and in relentless strategic bombing of North Vietnam.Many of the battles in Vietnam were technically United States victories, with the United States Army in control of the field afterward; holding territory gained this way proved difficult, however.