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
U.S.–German Peace Treaty (1921) to consent to ratification of the treaty, due in large measure to its objections to U.S. participation in the League of Nations. As a result, the two governments started negotiations for a bilateral peace treaty not connected to the League of Nations. On July 2, 1921, U.S. President Warren G. Harding signed the Knox–Porter Resolution, which had been passed by the U.S. Congress and ended the state of war between the U.S. and Germany, Austria and Hungary, further setting the stage for bilateral peace treaties. The treaty between the U.S. and Germany, formally titled the "Treaty between the United States