Opposing Forces and Strategy of the War

The number of combatants on both sides was originally small. As one side, however, raised the number of its forces or enlarged the scope of the fighting, the other would respond in kind. This increasing of military pressure was called escalation. At the high point of foreign involvement in mid-1969, United States troops numbered more than 540,000; South Korean troops, nearly 50,000; other Allied troops, a few thousand. By early 1973 all Allied troops had been withdrawn.

South Vietnam's regular army, the Army of the Republic of Vietnam (ARVN), numbered more than 400,000 troops. The ARVN was supplemented by 500,000 troops of the nation's two militia forcesfull-time Regional Forces and part-time Popular Forces. Marine, navy, and air force personnel numbered nearly 100,000.

The combined strength of the CommunistsVietcong guerrillas and North Vietnamese Army (NVA) regularswas estimated to number from 300,000 to 400,000 troops. The Vietcong consisted of full-time guerrillas organized into main force units, part-time guerrillas organized into local units, and part-time, unorganized fighters based in the villages. Many NVA troops were used to fulfill manpower requirements in the Vietcong main force units. Regular divisions of the NVA were also used, especially in the later phases of the war.

Although Allied forces vastly outnumbered Communist forces, the strategic situation of the war generally favored the Communists. Nearly all of the enemy in the south were used in combat, but the Allies had only half of their troops in combat. The remainder of the troops were used in such support activities as supply, construction, signal, and administration. The Communists controlled much of the countryside. The Allied forces held the cities.

During most of the war the fighting was not conducted in the conventional way, with armies facing each other along military fronts. Pitched battles between large opposing forces were infrequent. The Vietcong generally used guerrilla tacticssmall, harassing actions by nonuniformed fighters, who often lived in nearby villages. They could ambush troops sent against them, then melt away in the face of an attack. Terrorism, sabotage, and assassination were also Vietcong weapons.

The Allies had to make full use of their superiority in numbers, weapons, and air and sea power against the guerrillas. Their strategy was to use combat troops to root out the guerrillas through small search-and-destroy operations and wherever possible to wipe out the enemy's main force units in large-scale offensives called sweeps .

Air attacks and artillery bombardments were used to support combat troops and to destroy Communist bases and sources of supply. Allied aircraft also sprayed dioxin, a defoliant popularly known as Agent Orange, over areas of Vietnam to remove leaves and other vegetation hiding enemy bases and troop movements. ( )

In the last years of the war, following the withdrawal of Allied troops, the bulk of the fighting involved armies deployed along conventional fronts. The Vietcong guerrilla force had largely ceased being a factor.