> Most painful mistake was that right at the end of the cold war Russia wasn't strongly encouraged, even pressured or bribed to join NATO.

Because NATO works by consensus not majoritarianism, that would have given Russia a NATO veto, in effect. Despite that, Russia was on the NATO onramp from almost immediately after independence from the USSR until Putin demanded that Russia bypass the readiness criteria being applied to other new members and be immediately granted membership (and still technically was on the onramp after that, though no real progress was made between that point and when relations seriously started to degrade with Russia’s invasions of various of neighbors that were also, and more serious, NATO aspirants.)