This thesis examines the Scottish National Party (SNP) with respect to two of its most defining defence policies: its opposition to nuclear weapons, wanting to rid Scotland of the UK s nuclear deterrent based there, and its policy regarding a Scottish membership to the North Atlantic Treaty Organisation (NATO). It is a historical analysis of how the policies developed from the SNP s national breakthrough in the late 1960s, leading up to a discussion of the current situation where the party is playing a leading role in the ongoing campaign ending in an independence referendum on 18 September 2014. This inquiry argues that most scholars, journalists and military experts have understated the SNP s morally founded opposition to nuclear weapons, implying, for example, that the party would give up its policy in a situation where the rUK and NATO demanded it. By analysing how the policies have developed in the last four to five decades, we stress that the antagonism against nuclear weapons is deeply rooted in morality and therefore not easily negotiable in a possible settlement negotiation between Scotland and the rest of the UK. The NATO policy, however, has been much more wavering, from staunch opponents of a Scottish membership, to the current policy of wanting to apply if Scotland becomes an independent state, though only on conditions of removing the UK s nuclear deterrent from Scotland. This last aspect underlines why it has been important to look at both policies, since they are very much intertwined, though with very different developments and foundations.