American Military History, Volume 2 by Richard W. Stewart

As the Americans withdrew, South Vietnam's combat capability de- clined. The United States furnished its allies heavier M48A3 tanks to match the North Vietnamese Army's T–54 tanks and heavier artillery to counter North Vietnamese 130-mm. guns, though past experience suggested that additional arms and equipment could not compensate for poor skills and mediocre leadership. In fact, the weapons and equip- ment were insufficient to offset the reduction in U.S. combat strength.

In mid-1968, for example, some forty-five allied infantry battalions were present in South Vietnam's two northern provinces; in 1972, with U.S. infantry gone, only twenty-one battalions were in the same area. Artillery strength in the northern region suffered a similar decline, and ammunition supply rates fell as well. Similar reductions took place throughout South Vietnam, causing declines in mobility, firepower, intelligence support, and air support. American specialties (B–52 strikes, photo reconnaissance, and the use of sensors and other means of target acquisition) were drastically curtailed.