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
1962 in the Vietnam War military involvement in South Vietnam, provided that the government did not include President Diệm. That same month, North Vietnamese official Lê Duẩn instructed the leadership of the Viet Cong to avoid escalating the war by attacking cities as that might cause the United States to intervene in the war. The National Liberation Front in South Vietnam proposed to end the war in South Vietnam with a ceasefire, the withdrawal of American soldiers, and the creation of a coalition government of all factions pending elections. South Vietnam would become a neutral country, as were Cambodia and Laos, guaranteed by international treaty.