Defence Entrepreneurship: A Theory of Military Innovation Under Constraint

This article advances defence entrepreneurship as an analytical category to address a gap in military innovation studies, which privilege structural and systemic explanations while underspecifying the intentional action of actors who force change under constraint. Drawing on Posen, Rosen, Adamsky, Horowitz, Farrell and Biddle, the concept is defined through five constitutive dimensions: agentic initiative, risk acceptance, combinatorial novelty, strategic orientation and institutional embedding. A causal mechanism is articulated through three interconnected processes —time compression, risk assumption and option creation— that translate entrepreneurial agency into competitive advantage. The framework is illustrated through two contrasting cases: Israel's MAFAT-anchored ecosystem, built over decades of existential pressure, and Ukraine's Brave1-coordinated drone ecosystem, forged under wartime urgency since 2022. The comparison shows that defence entrepreneurship is not a single organisational template but a generalisable capacity realised through diverse institutional configurations, with direct implications for procurement reform, civil-military relations and the speed of capability generation.