 After the 1964 Gulf of Tonkin incident, the number of US soldiers in Vietnam escalated dramatically.McNamara and other US policymakers feared that the fall of South Vietnam to a Communist regime would lead to the fall of other governments in the region.In October 1966, he launched Project 100,000, the lowering of army IQ standards which allowed 354,000 additional men to be recruited, despite criticism that they were not suited to working in high stress or dangerous environments.