Russia isn't going into Romania or Bulgaria. Once they hit the border, it only becomes a question of timing for when they grab the Russian controlled bit of Moldova though.The frightening scenario is that if the Budjak area is taken, that puts Russia within the range of not only Moldova, but Romania and Bulgaria as well.
Russia invading a NATO country is just as much a redline at the moment as NATO deploying military forces into Ukraine/against Russia.
If Russia is prepared to eat the economic & diplomatic damage, they will be allowed to grab off Ukraine and that bit of Moldova (and no, Moldova won't be allowed into NATO before that). But Russia won't be allowed to go further.
While Russia would like to also grab off Lithuania, Latvia, and Estonia; they probably get bogged down enough in Ukraine to not make the attempt.
If Russia moves past Moldova towards Romania or Bulgaria, Turkey will move North to defend them even if no one else will. Turkey very much does not want to share a border with Russia.
Last edited: