Defenses National security -- 5 Civil defense -- 3 Military policy 3 Terrorism -- 3 Armed Forces 2 Armed forces 2 more ... Emergency management -- 2 Prevention -- 2 Weapons of mass destruction 2 Asymmetric warfare -- 1 Civil defense 1 Defenses -- 1 Disarmament 1 Disaster relief -- 1 Economic aspects 1 Foreign relations -- 1 Government policy -- 1 Harbors -- 1 Merchant marine -- 1 National security 1 Nuclear arms control 1 Nuclear terrorism 1 Nuclear weapons -- 1 Politics and government -- 1 Prevention 1 Security measures 1 Security measures -- 1 War on Terrorism, 2001-2009 1 World politics -- 1 less ...