Easter Offensive: On March 30, 1972, the People's Army of Vietnam (PAVN, the regular army of North Vietnam) launches an invasion of South Vietnam known as the Easter Offensive. The Army of the Republic of Vietnam (ARVN, the regular army of South Vietnam), with assistance from U.S. military advisors, struggles to hold the line against communist forces. Launched along three different invasion routes, this conventional mechanized invasion is a radical departure from previous North Vietnamese operations. Although the invasion is not designed to win the war outright, North Vietnam hopes to make significant territorial gains, destroy critical units of South Vietnam's military, and force the United States to abandon its support for the government of South Vietnam. In response, President Nixon orders a massive deployment of air and naval assets to the Southeast Asian (SEA) theater. U.S. Air Force, Navy, and Marine air units immediately begin flying large numbers of sorties in support of South Vietnamese forces. The objective of this campaign is to provide support for North Vietnamese military units on their massive advance into South Vietnam.