Tensions within NATO stem primarily from U.S. demands for higher defense spending by European members and disputes over involvement in Middle East operations, including the Iran conflict. The Trump administration has excluded several major contributors from select working-group meetings on alliance future planning, announced reviews of U.S. force posture that include potential troop and capability reductions in Europe, and floated criticism of under-spenders such as Spain. Formal withdrawal requires notification and adherence to treaty procedures, with U.S. law now mandating congressional involvement for any American exit. No member state has initiated departure proceedings, and recent alliance gatherings have produced statements of continued commitment despite internal frictions over burden-sharing and operational priorities. Scheduled defense ministerial reviews and spending target assessments through 2027 could influence cohesion.