This report presents four plausible and relevant scenarios for the United States' engagement and military presence in Europe during Donald Trump's current second presidential term (2025-2029). The aim is to outline a range of analytically grounded possibilities to help policymakers-primarily in European NATO countries-rise above the noise and make better-informed decisions in times of uncertainty. The scenarios are derived from the authors' understanding of the current political realities, observable trends, stated policy positions, and past behaviour by the Trump administration(s). They are informed by previous studies of US foreign policy, including its underlying drivers and institutional constraints. The four scenarios are: i) "Policy drift," where the US largely maintains its security and defence engagement in Europe near 2025 levels; ii) "Bilateralisation of US Engagement," where the US adjusts its military posture according to its bilateral relationships with European countries; iii) "Asia First," where the US tailors a military drawdown in Europe to enable a prioritisation of the Indo-Pacific; and iv) "Abandonment and regionalisation," where the US pursues a politically driven and disorderly retrenchment. All scenario descriptions finish by presenting indicators that may be used to assess whether a particular scenario is becoming more or less likely. The final chapter summarises the scenarios, identifies strategic consequences, and suggests tentative policy responses for Europe