Yes? Their options were invade Georgia BEFORE it's a NATO member, or allow a NATO-member Georgia to potentially host ABM interceptors at some point in the futur

Yes? Their options were invade Georgia BEFORE it's a NATO member, or allow a NATO-member Georgia to potentially host ABM interceptors at some point in the future, at which point they wouldn't be able to invade without fighting all of NATO. From a risk management perspective, for Russian leadership the choice is obvious.