President Dwight D. Eisenhower's "domino theory" influenced President Richard Nixon's approach to international relations with Southeast Asia by: President Nixon ordered covert U.S. bombing campaigns in Cambodia and Laos to help stop the spread of Communism in Southeast Asia. 1. The "domino theory" posited that if one country in Southeast Asia fell to Communism, it could lead to a chain reaction where neighboring countries would also succumb to Communist influence. This theory was a significant factor in shaping U.S. foreign policy during the Cold War era. 2. In response to this perceived threat of Communist expansion in Southeast Asia, President Nixon authorized covert bombing campaigns in Cambodia and Laos as part of the wider strategy to prevent the spread of Communism in the region. These actions aimed to disrupt Communist supply routes and infrastructure in an effort to contain the spread of Communism. 3. By ordering these covert bombing campaigns, President Nixon demonstrated his commitment to halting the advance of Communism in Southeast Asia, aligning with the principles of the "domino theory" and the broader containment policy pursued by the United States during the Cold War. In conclusion, President Nixon's decision to conduct covert U.S. bombing campaigns in Cambodia and Laos was directly influenced by the "domino theory" and the perceived threat of Communist expansion in Southeast Asia, reflecting his administration's efforts to contain and counteract the spread of Communism in the region.