single-tube rocket launchers. In the COSVN area of operations, consisting of the southern half of the country, seven infantry divisions (the 3rd, 4th, 5th, 6th, 7th, 8th and 9th) and one corps headquarters (4th Corps) were supported by only five battalions of field artillery, two of which were equipped with captured US-made weapons for which there was little ammunition, and three understrength armored battalions. The PAVN's 2nd Corps, with three artillery regiments belonging to its three infantry divisions, a corps artillery brigade, a tank brigade, and a separate armored battalion, could field a grand total of only 89 tanks and armored personnel carrier and 87 towed artillery pieces when it set off to attack Saigon in April 1975. Both the ARVN and PAVN's tanks and heavy artillery (field artillery and mortars 85mm or larger in caliber) suffered severe ammunition shortages. PAVN General Văn Tiến Dũng wrote that, compared to 1973, the 1974 ARVN's "firepower had decreased by nearly 60 percent because of bomb and ammunition shortages. Its mobility was also reduced by half due to lack of aircraft, vehicles, and fuel... The reduction of U.S. aid made it impossible for the puppet troops to carry out their combat plans and build up their forces." Reduction in firepower continued throughout the next year as the ARVN attempted to conserve ammunition. In the heavy fighting of July 1974 through March 1975, the ARVN expended an average of 18,267 tons of ammunition per month, compared to 66,500 tons per month in 1972, a more than 72% reduction. On the other side, PAVN's entire stock of heavy artillery and tank ammunition in 1974, including all ammunition held by combat units at forward warehouses, and in the PAVN's strategic reserves, totaled just 100,000 rounds. The ammunition problem was so serious that the PAVN artillery command had to replace the larger weapons in a number of units with obsolete 76.2mm and 57mm artillery pieces drawn out of storage for which there still was adequate ammunition. Consequently, the offensive would rely partly on captured ARVN stocks. Many historians maintain that given the massive reductions in US military aid to South Vietnam after 1973, any major PAVN offensive was bound to succeed. However, the ARVN's soldiers were hardened veterans, and South Vietnam maintained vast stockpiles of ammunition and equipment (as demonstrated by the massive quantities of war materiel captured by the PAVN when the war ended). The final