The Trump administration’s ongoing review of U.S. force posture in Europe, including announced reductions of several thousand troops and capabilities, reflects pressure for greater European burden-sharing rather than formal alliance exit. Congressional statutes, including the 2023 Kaine-Rubio provision, require prior legislative approval for any U.S. withdrawal from NATO, while a new bipartisan NATO Shield Act introduced in late September seeks additional oversight and expedited review. Administration officials have repeatedly stated there are no plans to leave the alliance, and recent NATO summits have reaffirmed collective defense commitments. These legal and institutional barriers, combined with European efforts to assume more conventional defense responsibilities, shape trader assessments of withdrawal likelihood ahead of any potential resolution date.