This study departs from existing scholarship by analysing and documenting nine cases of national 'success' to inform three primary objectives: (1) To catalogue cases of success for future reference; (2) To producing 'lessons' that may improve the effectiveness of interventions whilst reducing inadvertent negative outcomes; (3) To reconcile the discrepancy between national and international effects of interventions at the source. A comparison of the nine cases of national success found: (1) All governments perceived suppression as in its best interest; (2) All possessed authority throughout opium producing areas; (3) In all but two cases the state offered incentives from which farmers perceived some benefit to the cessation of opium production; (4) All governments possessed the capability to monitor opium farmers; (5) All interventions administered law enforcement. As these five factors presented across all or most cases they can be considered necessary for a successful outcome. Additional factors, which crossed more than one case, were deemed facilitative of the five necessary factors, and included: development-orientated approaches; community punishments; negotiated eradication; and conflict resolution/limitation. The findings suggest that the primary objective when planning a national intervention must be the establishment or maintenance of the five necessary factors. As such, premature eradication - which often deviates from the establishment/maintenance of the five necessary factors - represents an erroneous path, which can be costly in terms of time and resources. The case of Afghanistan is used to further clarify and explore the cross-case findings in a practical context.