During late 1971, U.S. and South Vietnamese intelligence estimates of communist intentions were mixed. An offensive was expected, but intelligence as to its timing, location, and size were confusing. The communists had mounted the Tet Offensive in 1968, but it had been conducted mainly by Vietcong (VC) in the initial phase, which had been destroyed in the process. Without VC support, a large-scale PAVN offensive was considered highly unlikely. A PAVN thrust across the DMZ was also considered unlikely. Past infiltration and offensive operations had been conducted through and from Laotian and Cambodian territory and a DMZ offensive would be a blatant violation of the Geneva Agreement, which North Vietnam was adamant in defending.