If Russia enters the war on Iran's behalf, it would provide crucial reinforcements via the Caspian Sea, enable China to reinforce Iran through the Belt and Road Initiative, offer financial backing using their resources as collateral, and crucially, place Iran under Russia's nuclear umbrella, negating the threat of tactical nuclear weapons use by Israel or the US.
Impact: High. Russian intervention would transform the conflict into a multi-front global war, significantly raising the stakes by involving China and neutralizing the nuclear threat, thereby prolonging the war indefinitely.
In the source video, this keypoint occurs from 01:02:52 to 01:04:36.
Sources in support: Professor Jiang (Geopolitical Analyst)

