Whatever you might have previously thought about settling your differences in exchange for guarantees of international protection, just look at how Ukraine has been rewarded for turning nuclear swords into ploughshares.
You seem to imply that we (the west) have abandoned Ukraine and allowed Russia to "invade".
Look at it another way - we stood by while the democratically elected President of Ukraine was overthrown by minority mob power. Russia have now justifiably intervened to shore up the democratically elected President...