Russia is keeping their expensive equipment in the back since years now because they're afraid to lose it. They would be fire bombing cities if they could. Russia already used white phosphorous in this war. The only reason they're not killing more civilians with missiles and drones is because they can't build more of them.

> No one is fire-bombing cities yet

That was mainly the Americans, British, and the Germans, not the USSR.

Also, what makes you think they could in this war? Do you think they can send bombers over Ukranian cities and drop a shitton of ordnance?

The Russians aren't deploying nukes; that is the only actual 'restraint' to date.

Wrong https://www.youtube.com/watch?v=r0BttoqSbeE

Russia has been attacking Ukrainian cities with missiles and drones since the beginning of the conflict. But Russia simply lacks the capacity to fire-bomb cities on a large scale. They only have a handful of operational heavy bombers left and no real ability to manufacture more so they're unwilling to risk them.