Russia Ukraine war, page-3828

I read that the nuclear "alert" was set to strategic assets, not tactical assets.

Strategic assets means ICBMs. You don't use ICBMs in a regional conflict.
The only reason they would be used is in a global nuclear war; which obviously results in mutual self destruction.

Even I don't think Putin is crazy enough for that.
But the scary thing is....accidents happen, and the higher the tension, the greater the risk of something unintentional happening on either side.