SIPRI topical backgrounder. Documents that Israel accounted for 27 per cent of Azerbaijan's major-arms imports across 2011–20 and 69 per cent across 2016–20; Russia 60 per cent in 2011–15 and 31 per cent in 2016–20. Pre-2020-war buildup of Israeli systems (Harop loitering munitions, Hermes-450 / Heron / Orbiter UAVs, ballistic-missile systems) is presented as the structurally decisive arms-supply relationship for the 2020 outcome.