Under the second Trump administration, US policy emphasizes a "NATO 3.0" framework that shifts primary responsibility for Europe's conventional defense to allies through troop reductions, command transfers to European officers, and reviews of force posture in Europe. Recent steps include announced withdrawals of several thousand US personnel from Germany, canceled or adjusted rotations, and exclusions of certain allies from planning groups, driven by demands for higher spending and support on issues like Iran. Full US withdrawal from the alliance faces significant barriers, including the 2023 Kaine-Rubio statute requiring congressional approval and a one-year notice period under the North Atlantic Treaty. Bipartisan legislation seeks to reinforce these checks, while administration statements indicate no current plans for exit. A six-month Pentagon review is due by early November 2026, with outcomes that could influence alliance dynamics without triggering formal departure.