Operation Lancaster II was a U.S. Marine Corps security operation that took place in northern Quảng Trị Province from 20 January to 23 November 1968 during the Vietnam War. The operation followed on directly from Operation Lancaster. The Marines patrolled aggressively. The response of the People's Army of Vietnam (PAVN) was mixed; Prolonged lulls alternated with fierce fighting. Broadly the Marines felt that they were successful in maintaining the supply route to Ca Lu, at the terminus of Route 9, and in, at least intermittently, disrupting PAVN communications.

Operation Scotland II was a U.S. Marine Corps security operation that took place in northwest Quảng Trị Province from 15 April 1968 to 28 February 1969.