Putin is not the type to nuke a city full of civilians, he will leave the escalation for the US and not fall into the trap the west set for Hitler in WW2. There are many other scenarios, Russia can supply allies with long range missiles, they can draw China into the war, they can escalate the war in the middle east, and if long range weapons are used against civilians in Russia, they will take out satellites.
Whatever Putin does, he will turn the people against the US and Western Governments, as they will see who the aggressors are.
