Recent challenges in the relationship between NATO and Russia have led to suspension of political and military cooperation. This thesis assesses the causal relationship between the gradual...Show moreRecent challenges in the relationship between NATO and Russia have led to suspension of political and military cooperation. This thesis assesses the causal relationship between the gradual deterioration of relations and NATO’s expansionism to Eastern Europe. This research uses process tracing of key events and developments to draw a historical pattern of the transformation in the relationship since the ending of the Cold War up until the Ukraine Crisis of 2014. To analyse the relation, this work uses a hybrid model of neorealist and social constructivist theories to understand power relations and motivations that underlie the developments. Overall, NATO’s eastward-enlargement to include former Soviet republics in its membership and its aspirations of creating a European-wide anti-ballistic missile defence system are identified as the main components that fuelled the deterioration in relations with Russia. Responding from a sense of insecurity, Russia has grown more assertive in regional politics to ensure its national interests. Russia has been able to project power in regional politics in aims of regaining its former power status. Russia’s increasingly confrontational stance has eventually manifested in military interventions in Georgia and Ukraine. The current suspension of relations does not constitute a structural new Cold War, but nevertheless is the product of an overall deterioration of relations.Show less