It's very doubtful that Russia's arsenal is totally functional. What are they fighting with in Ukraine? 90% Cold War inventory...and no easy way to retrofit anything. Nuclear silos, launch/firing systems HAVE to be maintained every 5-10 years. The US has done this religiously since the 1960s. The USSR did this as well, until 1991. An estimate from 2010 assessed that of Russian 7K nukes(IF the estimate is even that high) maybe 1K of them are fully functional.
Yes, 1K is still a daunting number but it pales to our 5K that ARE fully functional. China has them, but in the early 100s. North Korea? It's questionable how accurate their systems are firstly, and their total number is very low.
Putin does what the USSR did before him, that is to 'rattle the saber' trying to 'scare' the west into holding back help to Ukraine. We've already told him what would happen if he used tactical nukes...which is why he doesn't dare. His military would be destroyed fairly quickly.
We would know of course if he was going to use nukes, and if he did launch ballistic nukes we of course would answer and Russia would be effectively destroyed.
Putin is garbage, but he's not that stupid to dare attack us with Nukes. I believe if he did actually give that order, it wouldn't be followed and Putin would be taken out.