in 1935 fdr wanted the us to become a member of the, but was defeated in congress because of objections by isolationists

The correct answer is the International Court of Justice (known colloquially or informally as the World Court). President Roosevelt was highly committed to international cooperation, and in 1935 he fought, unsuccessfully, for U. S. membership in the World Court, the main judicial organ of the United Nations and the one that arbitrates legal disputes among UN member nations.

In fact, the United States has never had an easy relationship with the ICJ, and in 1986 it withdrew from that organ's compulsory jurisdiction, since the court ruled that it owed Nicaragua war reparations after having occupied it between 1912 and 1933.