Putin has more nuclear weapons. Shouldn't he decommission his first? He has already risked kicking off WWIII several times. He took a chunk of Ukraine, broke two chunks off of Georgia, make a bunch of border incursions into NATO/EU countries up north, and is currently supporting a civil war in Ukraine.
The situation is pretty crazy. Russia is far from the world's biggest economy, yet it is the nation with the greatest nuclear capability. There is clearly a desire to hold the rest of the world hostage, strongly equating fear with respect.
Note that Ukraine once had nuclear weapons. They gave them up, being assured that Russia would not threaten territorial integrity and that the USA would help ensure this. We see what those promises were worth. Giving up the nuclear capability was obviously a mistake. There is no way that Putin would have annexed Crimea under the threat of nuclear retaliation.