The report identifies conditions for the successful interactions of national security and defence stakeholders in the strategic framework of comprehensive security and integrated defence. It reviews the literature on comprehensive and integrated approaches to complex security and defence challenges and extracts some key factors underpinning the effective whole-of-government and whole-of-society efforts. It then considers experiences of several nations – Denmark, Finland, The Netherlands and Sweden – in building integrated security and defence systems. Finally, the paper investigates the ‘state of play’ in Estonia when it comes to implementing the concept of integrated defence. It closes with the recommendations to Estonia‘s policymakers.