This paper uses archival and secondary sources to consider the British experience in Acquisition of nuclear submarines (and especially the nuclear reactors) during the Cold War, focusing on the domestic and international challenges and legislation. It identifies that a well-articulated case for nuclear-powered submarine capabilities is necessary to justify the expense. It suggests that while technology transfer from a “donor” state is a very efficient means of starting up a project of this magnitude, reliance on an international partner for provision of key technologies and information long term renders the “client” state exceptionally vulnerable to the vagaries of domestic policy within the “donor” state. The British experience suggests that technology transfer as the impetus for development of a sovereign capability may be the optimum path.