In early May 1965, soldiers from the US Army’s 173th Airborne Brigade became the first American combat troops to land in Vietnam. The following month, Viet Cong forces launched what was dubbed their “summer offensive”: attacks on South Vietnamese units in provincial locations well outside Saigon. In mid-June, Viet Cong troops overran the provincial capital of Dong Xoai, killing hundreds of ARVN troops and civilians well as 20 American soldiers. These developments convinced the Americans that an even larger commitment of troops was required in Vietnam. On July 20th 1965, Secretary of Defence Robert McNamara suggested that President Lyndon Johnson increase the American contingent to 175,000 soldiers. Johnson’s military advisors called for an even greater commitment; defeating the Viet Cong, they argued, would require a half-million men and take five years. This Central Intelligence Agency (CIA) report, released on July 23rd, suggested that Viet Cong weaknesses and vulnerabilities were increasing, particularly in the areas of supply and civilian relations:
“The Viet Cong are well known as a wily and aggressive foe. Their so-called ‘summer offensive’ is a calculated effort to attack and destroy government forces in the provinces, under cover of the monsoon rains which hamper government reinforcement and resupply operations. Despite heavy casualties incurred in this effort, and in previous campaigns, the Viet Cong have managed over the years to increase their strength by means of infiltration and local recruitment of manpower in areas of South Vietnam under their control.
While not minimising their tenacity and resourcefulness, the Viet Cong also suffer serious liabilities and vulnerabilities which, if anything, have increased as the fighting has intensified:
1. The Viet Cong are now meeting less success in enticing South Vietnamese youths into their ranks and are resorting increasingly to draft and impressment to replenish their units and build new ones. Youths 16 and under have been captured in combat with Viet Cong main force battalions and found to have minimal training and low morale.
2. The Viet Cong appear to be increasingly employing local troops in areas remote from their homes. This tends to negate some of the advantages the Viet Cong have had of deep familiarity with the terrain and local conditions and easy access to the local populace for shelter and support.
3. Despite increased manpower from North Vietnam, including trained [NVA] regulators, these personnel suffer the same lack of familiarity with local geography and conditions…
4. Evidence that the Viet Cong are increasingly being equipped with [Soviet] bloc-manufactured weapons means that they are also plagued with longer supply lines and the need for extensive restocking.
5. Stepped-up harassment from the air, together with more government ground probes into Viet Cong areas, makes them more vulnerable to disruptions during periods previously devoted to training and food production, and to the destruction of or separation from their stockpiles.
6. The trend toward larger-scale Viet Cong attacks, and the more rapid and massive government retaliation through the use of jet aircraft, is causing the Viet Cong heavier casualties.
7. In recent months, Viet Cong defections have increased, and defectors and prisoners are reporting growing fear of air strikes and lower morale from increasing harassment.
8. Food is known to be short in some areas of central Vietnam, and poorer diets render them more vulnerable to illnesses; shortages of medicines is a problem for the sick and the wounded.
9. Lack of supplies is forcing the Viet Cong to extract more goods from the peasantry, thus increasing resentment of the populace against them; their larger force strength and needs has caused them in the past year or so to double or even triple taxation of the populace, in cash or kind.
10. Likewise, the Viet Cong have begun to shift what initially appeared to be a promise of land reform into forced peasant production for the Viet Cong.
11. The Viet Cong appear to be resorting increasingly to terrorism and controls to keep the peasants in line and cooperating.
12. …There are indications that growing numbers of the rural populace tend to blame the presence of the Viet Cong for bringing the war to their doorsteps and to regard them as increasingly unwelcome.”