Opium trade History 62 Opium 25 Commerce 20 Drug traffic 20 Drug control 19 Opium abuse 19 more ... Foreign relations 13 Politics and government 11 Social conditions 10 Histoire 8 Drug abuse 7 Voyages and travels 6 history 6 Government policy 5 Heroin abuse 5 Political aspects 5 Prevention 5 Colonies 4 Drug and Narcotic Control 4 Economic aspects 4 Economic conditions 4 Heroin industry 4 Law and legislation 4 Opioid-Related Disorders 4 Opiomanie 4 Sailors 4 Schooners 4 Social classes 4 Autonomy and independence movements 3 less ...