The design-enforcement gap in diamond sanctions: a three-round modified Delphi study of enforceability

Abstract Background Since 2022, the G7, the European Union and the United Kingdom have progressively restricted the import of Russian-origin diamonds. Diamonds present an unusually demanding test case for sanctions design because their physical properties make geographic origin difficult to establish once stones are cut, polished, mixed or re-exported. This study examines the enforceability of these measures—the practical capacity of frontline authorities and supply-chain actors to detect, evidence and act upon breaches. Method This study conducted a three-round modified Delphi study with an international panel of experts drawn from academia, government and enforcement, non-governmental organisations, and the diamond industry. Round 1 used four open-ended prompts, analysed through inductive thematic analysis, to identify constructs of enforceability. These were expressed as Likert-scaled items rated in Rounds 2 and 3. Consensus was pre-specified as at least 75% of ratings in the top two response categories, combined with an interquartile range (IQR) of no more than 1. Stability across rounds was defined as an unchanged median and a mean shift of no more than 15%. Results 32 participants completed Round 1; 30 were retained in Round 2, and 19 in Round 3, consistent with attrition ranges reported for Delphi studies. Six enforceability constructs were assessed. The panel reached consensus that ‘political will and governance’, ‘enforcement capacity’, ‘legal and policy innovations’, and ‘mandatory traceability mechanisms’ are central to enforceability. Two constructs—the effectiveness of technological fixes and the feasibility of cultural change in the industry—showed agreement below the consensus threshold, exhibiting stable divergence across rounds. Qualitative rationales attributed the enforceability deficit to the low knowability of diamond origin, the operational burden these places on frontline authorities, and the absence of an institutionalised enforcement voice in the design of the measures. Conclusions Experts perceived a persistent gap between the design of diamond sanctions and their enforceability. The panel’s reasoning supports an ‘enforceability first’ approach that embeds frontline operational input at the design stage, uses civil-recovery pathways as a complement to (not a substitute for) criminal enforcement, and treats traceability as a governed system rather than a technological solution. The findings are exploratory and reflect expert perception rather than measured breach rates; they nonetheless offer transferable insight for commodities where origin is difficult to verify.