I suggest NATO launch war, retake Ukraine, and deprive Russia of 60% of its military for almost no cost.

This will be followed by Putin having to spend the next 40% of its military on keeping order within Russia. If he will use nukes, he will obviously not be able to do so (NATO nuclear retaliation will destroy at least 50% of remaining Russian military.)

Even if Putin will stay in power, sending military to police innumerable Russian cities, and towns will take him off the list of potential threats for next decade at least.

Use the time won to remilitarise the West.