If Ukraine ever makes the mistake of concentrating most of its forces in one place, tactical nukes might be useful. Otherwise they just make a huge mess of con

If Ukraine ever makes the mistake of concentrating most of its forces in one place, tactical nukes might be useful. Otherwise they just make a huge mess of contested ground. That tends to make things worse for the invader than for the defender. (This assumes that Putin doesn't want an empty, desolate, ruined Ukraine as Russia's buffer against NATO, being prepared to give up Sevastopol for it. At this point Ukraine has a lot of industrial capacity and a lot of natural resources Russia could still exploit.)