There's no way the World would just stand by and watch Putin launch tactical nukes as a country and not do anything. That would be an incredibly dangerous precedent to set for World politics.But wouldn't turning this into Putin's Afghanistan cause casualties to skyrocket? I can also see Putin getting frustrated and using tactical Nukes if this drags on. I also don't see any deterrent against him using Nukes in Ukraine as it wouldn't result in MAD.