National security Intelligence service 2 National security -- 2 Prevention 2 Security, International 2 Terrorism -- 2 Civil defense 1 more ... Civil defense -- 1 Defenses 1 Democratie 1 Economic aspects 1 Government policy 1 Harbors -- 1 International relations 1 Merchant marine -- 1 Military art and science--History--21st century 1 Military art and science--Technological innovations 1 Nationale veiligheid 1 Overheidsbeleid 1 Politics and government -- 1 Security measures 1 Security measures -- 1 Security systems 1 Security, International -- 1 Strategy 1 Technological innovations--Political aspects 1 Technology and state--History--20th century 1 War on Terrorism, 2001-2009 1 less ...