A new shade of balancing in the balance of threat theory

”How is defence cooperation effected due to a perceived imbalance of threat?” When faced with a threat, the balance of threat theory implies that states ally in order to aggregate capabilities to deter the threat. However, states have multiple options to increase security by adding military power, with internal balancing on the one side and external balancing on the other. In order to better explain actions taken by states to balance a threat, a new shade that does not include defence obligations is needed for the balance of threat theory. In this paper, changes in defence cooperation is that shade. By including changes in defence cooperation as a response to increased threat, for example the purchase of defence materials, joint training and defence planning, the balance of threat theory can expand its current explanatory power. Also, by understanding these changes states can prepare for it in advance and react on short notice, since today’s security environment changes rapidly. To study if changes in defence cooperation can be included into the balance of threat theory, Swedish defence cooperation with three partners (NATO, Finland and within NORDEFCO) are examined before and after the aggressive behaviour by Russia in 2014. The results are distinct and unitary, all cooperation changed to a more alliance-like purpose, to counter threats by presenting combined strength, but without formal or informal defence obligations. These actions strengthened the capability to function together by enhancing interoperability and preparing for common action in peace, crisis and conflict