This report examines the main political tensions impacting NATO's unity, cohesion, and integration of military resources, crucial for effective deterrence and defence. It highlights the critical role of US leadership in sustaining NATO's unity and military capability, emphasising the impacts of tensions in the transatlantic relationship. It moreover highlights extra- and intra-European tensions that may influence NATO's unity and cohesion in the years to come. It begins by providing a structural perspective, exploring the escalation of global tensions and shifting power dynamics, revealing a security landscape marked by heightened strategic competition and increased uncertainty. The core research question addresses political tensions that may affect NATO's ability to achieve its task of deterrence and defence in Northern Europe up to 2030. The study identifies three main sources of political tensions. First, differing threat perceptions, priorities, and policy preferences among NATO members significantly impact their security strategies, resource allocation, and cooperation. Second, political tensions arise from how European states and the EU manage their external relations. Third, intra-European relations contribute to tensions, including disagreements among major European powers, domestic challenges to unity, and differing views on cooperation, particularly regarding the European defence industry. This report is part of the broader study, Western Military Capability in Northern Europe 2023-2024, contributing to a comprehensive analysis of the military strategic situation in Northern Europe