European nations and Canada may not want to be associated with some U.S. military actions

Study and practice of how sovereign states, international institutions, and non-state actors interact across borders. Encompasses diplomacy, negotiation, alliances, and conflict — the foundational domain through which global order is constructed, contested, and maintained.

Overview of major milestones in the evolving relationship between the United States and NATO.

The alliance's cooperation with Western partners: collective defence and deterrence, defence-industrial and technology investment, burden-sharing and the coordination of military support among member states and allied governments.