Civil defense -- Defenses 2 National security -- Terrorism -- 2 Civil defense 1 Emergency management -- 1 Government policy -- 1 more ... Harbors -- 1 Merchant marine -- 1 National security 1 Politics and government -- 1 Prevention 1 Prevention -- 1 Security measures 1 Security measures -- 1 War on Terrorism, 2001-2009 1 less ...