The return of Donald Trump to the White House has exposed a growing mismatch between the United States’ “America First” policy and its established role as the principal coordinator of transatlantic sanctions. This article examines how US–EU sanctions coordination changed in 2025 and assesses whether these changes represent temporary policy divergence or a more systemic transformation of the transatlantic coalition. The study combines Robert Putnam’s two-level game model with the concepts of wedging and binding. This analytical framework links domestic political constraints and ideological alignments to the cohesion of international coalitions. Empirically, the article applies process tracing to three episodes: the US decision not to introduce new sanctions against Russia on 24 February 2025; Washington’s refusal to support the EU initiative to lower the price cap on Russian oil in June–July 2025; and the unilateral US sanctions against Rosneft and Lukoil in October 2025, including subsequent exemptions and implementation delays.

The analysis yields four principal findings. First, the United States retained the sanctions inherited from the previous administration but reduced its proactive and coordinating role in developing new measures. This combination of regime continuity and declining leadership increased the asynchrony of US and EU sanctions policies without producing a complete breakdown of the sanctions coalition. Second, Washington increasingly preferred unilateral and discretionary measures over prior coordination with European partners. Even when these decisions were not explicitly designed to divide the coalition, their repeated use produced a cumulative wedging effect by weakening established expectations of consultation, predictability, and burden sharing. Third, the October sanctions against major Russian oil companies did not signify a restoration of the previous coordination model. They were primarily linked to US bilateral diplomacy with Russia and domestic demands for a tougher policy, while exemptions granted to Hungary and delays in implementation demonstrated the selective and transactional character of the new approach. Fourth, the European Union responded through binding strategies intended to preserve the appearance and institutional framework of transatlantic unity. These strategies included public declarations of solidarity, the rapid incorporation of unilateral US decisions into a collective sanctions narrative, diplomatic engagement with the US Congress and executive agencies, and closer cooperation with the United Kingdom. Their effectiveness, however, was constrained by the EU’s internal fragmentation and unanimity requirements.

The article further identifies ideological convergence between the Republican governing elite in the United States and Eurosceptic actors in Europe as an emerging mechanism of coalition fragmentation. Selective exemptions and privileged bilateral arrangements may place individual EU member states in differentiated legal and political positions, thereby undermining common European sanctions discipline. The findings suggest that transatlantic sanctions coordination is shifting from an asymmetrical but relatively predictable US-led model towards a fragmented and situational arrangement. Under this model, collective action depends less on institutionalised American leadership and more on temporary alignments among the United States, EU institutions, individual European governments, the United Kingdom, and domestic political actors. The transformation of sanctions coordination therefore reflects a broader revision of transatlantic commitments: sanctions are becoming less an expression of Western political unity and more an arena in which internal disagreements, ideological affinities, and competing national interests are negotiated.