(Reuters) – Russian President Vladimir Putin said at the weekend that his nation’s nuclear forces should be put on high alert, raising fears that Russia’s invasion of Ukraine could lead to nuclear escalation. Here is how Russia’s chain of command would work in the event of a nuclear weapon launch. WHO DECIDES TO LAUNCH RUSSIAN NUCLEAR WEAPONS? A 2020 document https://archive.mid.ru/en/web/guest/foreign_policy/international_safety/disarmament/-/asset_publisher/rp0fiUBmANaH/content/id/4152094 called “Basic Principles of State Policy of the Russian Federation on Nuclear Deterrence” says the Russi…