National security National security -- Civil defense 1 Civil defense -- 1 Defenses 1 Economic aspects 1 Harbors -- 1 more ... Intelligence service 1 Merchant marine -- 1 Politics and government -- 1 Prevention 1 Security measures 1 Security measures -- 1 Security, International 1 Security, International -- 1 Terrorism -- 1 War on Terrorism, 2001-2009 1 less ...