Since the United States is considered the only world superpower at the end of the cold war, the United States has played an important role in maintaining world order.
Among other reasons, the US has been involved mainly to offer tranquility, that is, his military presence suppresses suspicions in Europe and Asia that could otherwise be felt and could lead to unhappy political results.
The United States also leads the effort to prevent the spread of nuclear weapons to dangerous regimes or groups.
