Total defense has, in the past decade, become a renewed mainstay on the Swedish political agenda, and the goals are clear regarding what the civilian and military components of the Swedish total defense should achieve, both independently and together. Despite this clarity, there is no clear scientific consensus on whether the inter-organisational collaboration that is required in total defense is functioning effectively. This study aims to shed light on the effectiveness of civil-military collaboration in the case of total defense planning on Gotland, the largest island by area in the Baltic Sea and among the most strategically valuable NATO assets in the region. The results show that four factors of network effectiveness (goal consensus, number of participants, need for network-level competencies and trust) contribute in various ways to the effectiveness of collaboration on Gotland. These factors help establish a shared understanding of objectives, enable civilian actors to understand and appreciate the aims of total defence planning and allow actors to utilize each other’s capabilities, to achieve said common goals.