The Principal Policy and Decision-making Institutions of the Alliance Key to the Principal NATO Committees 30. High Level Group (NPG/HLG) Members All member countries except France. Chairman National Chairman (United States). Role Advisory body to the Nuclear Planning Group (NPG). Meets several times per year to consider aspects of NATO's nuclear policy and planning. Levels National experts from NATO capitals. Principal Subordinate Committees N/A. International Staff Support Division of Defence Planning and Operations (Nuclear Policy Directorate).