1973 in the Vietnam War for the U.S. Christmas bombing (Operation Linebacker II) and that "we deplore the action." President Nixon wrote a letter to President Nguyen Thieu of South Vietnam asking for Thieu's cooperation in the Paris peace negotiations and stating that "the unity of our two countries...would be gravely jeopardized if you persist in your present course." Thieu had scuttled a draft peace agreement reached in October 1972. Nixon pledged to respond with "full force" if North Vietnam violated the peace agreement. As U.S. National Security Adviser Henry Kissinger prepared to resume peace talks with North Vietnam in Paris, United States President Nixon
1973 in the Vietnam War Nixon promised continued economic aid to South Vietnam, dependent upon U.S. congressional approval, and Thieu pledged to never ask the United States to reintroduce American troops into South Vietnam. The US and North Vietnam issued a joint communique calling on all parties to observe the 28 January ceasefire agreement with effect from 15 June. The Case–Church Amendment approved by the U.S. Congress and signed into law prohibited further U.S. military activity in Vietnam, Laos and Cambodia after 15 August 1973. This ended direct U.S. military involvement in the Vietnam War, although the U.S. continued to provide military equipment and economic