	Introduction

On May 9, 2007, President George W. Bush issued National Security Presidential Directive (NSPD) 51, which is also identified as Homeland Security Presidential Directive (HSPD) 20 (NSPD 51/HSPD 20), on National Continuity Policy. NSPD 51/HSPD 20 updates longstanding continuity policy expressed in various directives issued by previous administrations to assure that governing entities are able to recover from a wide range of potential operational interruptions. Continuity planning is not unique to government; efforts to assure essential operations are broadly integrated into many private sector industries. Unlike the private sector, however, federal continuity planning also incorporates efforts to maintain and preserve constitutional government, on the assumption that certain essential activities typically provided by government must be carried out with little or no interruption under all circumstances.
On May 9, 2007, President George W. Bush issued National Security Presidential Directive (NSPD) 51, which is also identified as Homeland Security Presidential Directive (HSPD) 20, on National Continuity Policy. The directive updates longstanding continuity directives designed to assure that governing entities are able to recover from a wide range of potential operational interruptions. Executive branch efforts to assure essential operations are similar to those that are broadly integrated into many private sector industries. Government continuity planning also incorporates efforts to maintain and preserve constitutional government, based on the assumption that certain essential activities typically provided by government must be carried out with little or no interruption under all circumstances.