Declassified per Executive Order 13526, Section 3.3
NND Project Number: NND 63316. By: NWD Date: 2011
in all available estimates throughout the years 1954–1960. No U.S. estimate that it was likely the VPA would overtly invade South Vietnam during that period has been found; on the contrary, in spite of insistence by Diem that invasion by the DRV was a serious possibility,46 U.S. estimates continued to stress that such an invasion was unlikely. In the words of the Joint Chiefs of Staff, engaged in the business of determining U.S. policy in the event of aggression in Vietnam, "the Joint Chiefs of Staff are of the opinion that at this time the major threat to South Vietnam continues to be that of subversion...."47
In a somewhat later period it was stated that "The North Vietnamese Army is almost twice the size of the South Vietnamese Army. The threat posed by the large northern forces has put constant psychological pressure on the GVN."48 In view of the nature of the U.S. response to the combined threat posed by the sects, the Viet Minh in South Vietnam, and the VPA as reflected in the missions assigned the forces of South Vietnam, it would appear that this "constant psychological pressure" had telling effects on U.S. as well as GVN policymakers.
