Answer and Explanation:
What are international organizations?
International organizations are institutions in which several countries participate, that is, intergovernmental institutions. They serve as a space for countries to adjust their international policies regarding several kinds of issues: economics, health, trade, etc. We can say the purpose of international organizations is to find solutions and paths that present gains for all involved and, in some cases, for the whole world.
Why should the United States be a part of them?
Being a part of international organizations, the U.S. can advance its policies, influence other countries to conform to rules and principles, coordinate efforts and resources to the benefit of all involved, etc. Of course, being a part of an organization will bring with it demands and sacrifices. However, the consequences are beneficial as the U.S. becomes more influential, being a part of decisions and plans that affect Americans as well as other peoples.