The purpose of this subchapter is to provide a system of emergency preparedness for the protection of life and property in the United States from hazards and to vest responsibility for emergency preparedness jointly in the Federal Government and the States and their political subdivisions. The Congress recognizes that the organizational structure established jointly by the Federal Government and the States and their political subdivisions for emergency preparedness purposes can be effectively utilized to provide relief and assistance to people in areas of the United States struck by a hazard. The Federal Government shall provide necessary direction, coordination, and guidance, and shall provide necessary assistance, as authorized in this subchapter so that a comprehensive emergency preparedness system exists for all hazards.