percent of rural dwellers in Vietnam lived in "relatively secure villages." North Vietnamese documents suggest that one reason for the 1972 North Vietnamese offensive was to reverse the progress made in pacification. CORDS, and U.S. participation in hearts and minds programs, effectively ended after the withdrawal from Vietnam of the last U.S. ground forces in August 1972. Assessment of hearts and minds programs The success of hearts and minds programs in Vietnam was ambiguous in the words of Richard A. Hunt in his book Pacification. The high-level officials in the CORDS program claimed large successes. Some historians, however, maintain that pacification programs failed to dislodge the Viet Cong from their position of strength in the countryside. After a long history of failed pacification programs, the successes reported for CORDS in the 1968–1972 period were partially attributable to the heavy casualties the Viet Cong suffered during the Tet Offensive and subsequent actions in 1968. The number of Viet Cong infrastructure is estimated to have been reduced from 84,000 in 1968 before Tet to 56,000 in 1972. However, although the number of battalion-size battles declined, the number of small unit actions by the Viet Cong nearly doubled during the same time period, illustrating the impact of hearts and minds (as believed by its advocates). In January 1972 Ambassador Bunker warned that the communists would have to "mount a major military offensive...to prove his public claims that Vietnamization and pacification are failures." True to Bunker's prediction, on March 30, 1972, North Vietnam launched its Easter Offensive. Although South Vietnam, with American air support, withstood the offensive, the North Vietnamese army gained control over sizable areas of South Vietnamese territory and displaced more than one million people. Komer attributed the ultimate failure of hearts and minds programs in South Vietnam to the bureaucratic culture of the United States in addition to the administrative and military shortcomings of the South Vietnamese government. A counter-insurgency strategy for Vietnam was proposed from the earliest days of U.S. involvement in Vietnam, notably by Presidents Kennedy and Johnson, but there was an "immense gap between policy and performance." Early efforts to implement hearts and minds programs in Vietnam were small scale compared to the resources and manpower devoted to fighting a conventional war. Even after the creation of CORDS in 1967, "pacification remained a small tail to the very large conventional military dog. It was never tried on a