Foreign Policy: Foreign policy refers to a government's strategy for dealing with other countries. It includes decisions regarding diplomacy, military actions, trade agreements, humanitarian efforts, etc.
Isolationism: Isolationism is a foreign policy approach where a country avoids involvement in international conflicts and focuses on its own affairs. The U.S followed an isolationist policy during certain periods in its history.
Alliance: An alliance is a formal agreement between countries to support each other militarily, economically, or politically. NATO (North Atlantic Treaty Organization) is an example of a military alliance involving the U.S and other nations.