This chapter examines the foundations of the bargain from the British point of view and its evolution since the end of the Cold War. It draws out the extent and nature of the United Kingdom’s (UK) current commitments to North Atlantic Treaty Organization (NATO). The chapter discusses the factors affecting the UK’s role, interest, and position within NATO in the present and the foreseeable future, ranging from its perspective of emerging security threats to the domestic foundations of British defense policy and contribution to, the Alliance. The UK was the keenest among Europeans to embed Washington in Europe’s post-war security order, and its early foreign policy choices heavily influenced the original design of the Alliance. Demonstrating leadership in the maritime domain, enabled through continued investment in maritime capabilities, has been a key aspect of UK’s transatlantic engagement.