Contributor(s): Admiral Sir Mark Stanhope, Professor Mary Kaldor | The inter-relationship between global and national security is a feature of our connected world. Rapid change and uncertainty in the global strategic environment is bringing new security challenges. Emerging powers are morphing into future strategic competitors, competition for resources is increasing, non state actors are challenging state assumptions about security and the effectiveness of supranational institutions is being questioned. The potential for challenges to other states to impact upon our national interests is becoming better understood. At the same time, more traditional threats to defence and security cannot be discounted. States need to think afresh about the scope and delivery of their responsibilities for the security and well being of their citizens. Admiral Sir Mark Stanhope, the First Sea Lord and Chief of Naval Staff of the Royal Navy, considers the implications for states, now and in the future. Mary Kaldor is Professor and Co-director of LSE Global Governance, LSE. David Held is Graham Wallace Professor of Political Science and Co-Director, Centre for the Study of Global Governance, LSE.