Technically we are already there. The bigger question is how far it will escalate, and whether slow walking it isn't the best guarantee that it will eventually spiral out of control. The West is happy to sit back and watch Ukraine get slaughtered as long as it isn't their territory that is involved, absorb the refugees (the ones that survive, that is) and then pretend to get back to business as usual.

But Putin's appetite is not satisfied and once he has 'won' Ukraine (or whatever remains standing there) for sure he will push on. Moldavia was apparently already on the menu, I can easily see another sortie from Belarus into any one of the Baltics (Estonia, Lithuania, Latvia in that order). This is far from over.