This paper studies the incident where a Soviet submarine later called U-137, ran aground in the Swedish archipelago during the 1980s. The main motivation behind this study is the lack of studies focusing on nuclear crisis management featuring a superpower and a smaller state. Specifically, on so called “Close calls” that describes crises and conflicts where the use of nuclear weapons has been considered intentionally but also unintentionally when nuclear weapons were at risk of detonation. Former studies have mostly focused on nuclear crises between the USA and Soviet. This led to the question of this study: How can we describe the co-operation between the state actors dealing with the U-137 crisis? To analyze the case the theory ”An Integrative Framework for Collaborative Governance” written by Kirk Emerson, Tina Nabatchi and Stephen Balogh. The theory is prescriptive and tries to explain how the co-operation within states, companies, governments etc, should act to initiate, maintain and maximize their potential. Using this theory the author can identify factors within that help to better understand how to co-operation during the crisis unfolded and ultimately lead to its ending.