There was serious discussion in Washington of nuking China after China's entry into the Korean war. (Specifically, nuking concentrations of rice fields, causing starvation until the Beijing relents, at which time Washington would provide food aid.)

When in the 1960s tensions between Moscow and Peking rose, Moscow asked Washington if Washington would be okay with Moscow's nuking China. (Washington replied with a firm no.)

Although Russia is probably not going to resort to nukes, the risk is high enough that I wish my country (the US) had started drastically increasing American preparedness for nuclear war when it started sending military aid to Ukraine.

Given the catastrophe risk involved in their use, there is much to be alarmed at simply to consider the possibilities of accident use - miscommunication, false alarms, broken technology, etc.

It takes more than one thing going wrong at the same time, for an accident to happen, but that happens - that's why we have car accidents - only here we're talking about a potentially civilization/climate ending accident.

Better not to be in that situation in the first place.

This logic fails at first scrutiny, look up Salami tactics.