 This tendency has strengthened since the end of the Cold War, partly because of the strong discouragement of humanitarian engagement with VNSAs in counterterrorism legislation and donor funding restrictions.In their opinion, further study is necessary to identify ways in which humanitarian agencies can develop productive dialogue with VNSAs.The International Security Department and the International Law Programme at Chatham House are seeking to understand the dynamics that will determine support for a principle-based approach to engagement by humanitarian actors with VNSAs.