Was the U.S. involved in any treaties that contributed to our involvement in this war?

In 1954, the United States signed the Manila Pact (Southeast Asia Collective Defense Treaty) and became a member of the Southeast Asia Treaty Organization. The SEATO was established after the French left Indochina and was created alliances to oppose further Communist gain in Southeast Asia. They Promised to help South Vietnam not only financially but also with the military training and improving mutual social and economic issues. This organization was also created to legitimize the United States' presence in South Vietnam. The same year when SEATO was created, the Manila Pact was signed. It was created to find peaceful ways to resolve differences in Southeast Asia by establishing a council to determine how to implement the treaty and to provide consultation for military and other planning within the treaty area.