A country in the far east where the US tried to preserve freedom?

The country you're referring to is likely Vietnam. During the Vietnam War, the United States intervened in an effort to prevent the spread of communism in Southeast Asia, believing that the fall of Vietnam to communism would lead to further regional instability. This conflict was marked by significant military engagement and profound social and political consequences, ultimately resulting in the unification of Vietnam under communist control in 1975. The war remains a contentious chapter in U.S. history, reflecting complex issues of foreign policy and national interests.