Despite years of political goodwill and a shared concern over China's military rise, Japan and India have made little concrete progress in defense technology cooperation, with structural barriers around technology transfer, cost competitiveness, and industrial control continuing to stall major deals. Tokyo has recently overhauled its arms export rules and passed legislation to strengthen its defense industrial base, while New Delhi is diversifying away from Russian suppliers — conditions that should theoretically open the door to deeper bilateral engagement. Yet with only one completed joint project to date and flagship negotiations like the US-2 amphibious aircraft deal still unresolved, analysts warn that political enthusiasm has yet to translate into the kind of scalable, fast-moving cooperation both countries may need as drone warfare and AI-enabled systems reshape the security landscape across the Indo-Pacific.