This is more like trying to fight fire with cancer - not effective and likely to backfire.
Russia is not going to come apart, especially not areas close to the capital. And if it did, you would have thermonuclear weapons in the hands of rando’ nobodies.
So you are saying that Biden should use his newly acquired presidential immunity to assassinate Trump with Novichok and claim Putin did it.
He will get Republican support for the war in Ukraine and shore up his presidency. And if it is found out that he did it, suffenly this law will be unpopular with republicans and get overturned! Win-Win-Win!
Indeed I think the west is better sticking to pushing for rule of law, secure borders, human rights and the like.
IMO on Ukraine they should have said invading a basically peaceful democratic state to grab its land is unacceptable and we'll support Ukraine winning and taking their land back with whatever weaponry necessary. Instead of the wishy washy, no real goal, drip feed some weapons to get a stalemate where Russia keeps some land. Why still no f16s two and a half year in? Why can't Ukraine hit the airfields they are bombed daily from and so on? Why won't the US govt say they'd like Ukraine to win? Even if they don't, just saying it would be a good tool to scare the Russians into better negotiations.
I'm not sure you necessarily want to fight fire with fire?