Countries haven't sent troops to Ukraine. I think its the fear of nukes that's the reason
It’s the fear of soldiers returning in body bags, not nukes.
None of the ex Warsaw pact countries have an issue with that. They understand the importance of stopping Russia. The only reason they're not sending troops to Ukraine is because Putin has thrratened with nukes.
For the rest of Europe its a mixed bag. Basically, the more they feel threatened by Russia because of geography, the more they are willing to sacrifice. Be it weapons, money or troops.
Personally I think we should commit troops. Stop being pussies. The more the nuke threat works, the more it'll be used. So in order to make that threat to not be used, we need to ignore it. I think its the least dangerous option, long term