PurposeThis paper aims to contribute to the literature on the changing role of the defence sector in the economy at industry and enterprise levels focusing on defence‐civilian cooperation and defence supply networking with foreign industry enterprises from complex industry‐perspective.Design/methodology/approachMeasuring is based on the comparative industry data and the unique survey evidence for the Slovenian defence industry enterprises to derive managerial and policy implications.FindingsThe role of the defence industry in the economy declined, but trade deficits from arms and ammunition increased. The industry enterprises can gain from defence‐civilian cooperation and defence supply chain networking with foreign industry enterprises. Information‐coordination institutions are seen to provide opportunities for future industry development in Slovenia.Research limitations/implicationsThis research focuses on Slovenia. Future enhancement of the research would be to look into the possibility of applying the findings to other countries. The size of the enterprise, and even more the size of the country, does matter in the defence‐market chain activities.Practical implicationsThe proposed industry firm‐level survey approach provides useful policy and managerial implications in the evaluation of defence industry supply and market chain cooperation and networking activities with foreign industry enterprises. The study proves the usefulness of the results, both to the future organizational development and as a decision‐making tool in the complex industry systems.Originality/valueThis paper adds to the industry firm‐level analyses as data management tools for evaluating the defence‐civilian cooperation and networking of complex industry market chain activities for more effective management.