Government policy Emigration and immigration -- 22 Terrorism -- 16 Refugees -- 11 Government policy -- 10 Prevention -- 9 Prevention 8 more ... Immigrants -- 5 Climatic changes -- 4 Environmental aspects 4 Global warming -- 4 Economic aspects 3 Human rights 3 Refugees 3 Social aspects 3 Terrorism 3 Commercial policy 2 Globalization 2 Greenhouse gas mitigation -- 2 International cooperation 2 Internet -- 2 Internet governance 2 National security 2 National security -- 2 Politics and government 2 Racism -- 2 Television broadcasting -- 2 Women -- 2 Agricultural subsidies 1 Alien labor -- 1 less ...