Threats against security in the Internet often have a wide-range and can have serious impacts within society. Large quantum computers will be able to break the cryptographic algorithms used to ensure security today, which is known as the quantum threat. Quantum threats are multi-faceted and very complex cybersecurity issues. We use assemblage theory to explore the complexities associated with these threats, including how they are understood within policy and strategy. It is in this way that we explore how the governance of the quantum threat is made visible. Generally, the private and academic sector have been a primary driver in this field, but other actors(especially states) have begun to grapple with the threat and have begun to understand the relation to defence challenges, and pathways to cooperation in order to prepare against the threat. This may pose challenges for traditional avenues of defence cooperation as states attempt to understand and manage the associated technologies and perceived threats. We examine how traditionally cooperating allies attempt to govern the quantum threat by focusing on Australia, Canada, the European Union (EU), New Zealand, the United Kingdom (UK), and the United States (US). We explore the linkages within post-quantum cryptographic assemblages and identify several governmental interventions as attempts to understand and manage the threat and associated technologies. In examining over 40 policy and strategy-related documents between traditionally defence cooperating allies, we identify six main linkages: Infrastructure, Standardization, Education, Partnerships, Economy, and Defence. These linkages highlight the governmental interventions to govern through standardization and regulation as a way to define to contours of the quantum threat.