Ukraine's end game is to try to bleed Russia until they decide to withdraw. I don't think "hitting back" is ever on the table, if you mean Ukraine invading Russia. That's not going to happen.
Russia could still unload a few nukes. If you can't take Kiev, you can always nuke it. But that has a number of problems. One of the smaller ones is it's really hard to maintain the "oh, that's not really an independent nation, they're really part of Russia" lie when you nuke them.
Russia could still unload a few nukes. If you can't take Kiev, you can always nuke it. But that has a number of problems. One of the smaller ones is it's really hard to maintain the "oh, that's not really an independent nation, they're really part of Russia" lie when you nuke them.