Here is an alternative perspective.
NATO is playing a very dangerous game of chicken. All Russia needs to do is to surface and expose ONE Boomer in either the North Sea, in the Atlantic, West of France, or in the Med.
NATO is surrounded by nukes. Go ahead, play chicken with Russia. There is no logical reason to assume a Russian strike would ONLY come from the East!!
I wonder if both sides US/Russia have the ability to always know where all of the others Nuke subs are at all times? And if they do is there ability to destroy them in a moment before they can launch their deadly missiles? Seems doubtful. If those missiles have multiple independently targeted warheads on each one, just one sub could have catastrophic destructive capability. M.A.D. indeed.