What about massive nuclear mines laid in front of their routes? Or long range nuclear missiles fired from ships? Long range torpedoes? Kamikaze-style mini subs?

What about massive nuclear mines laid in front of their routes? Or long range nuclear missiles fired from ships? Long range torpedoes? Kamikaze-style mini subs? A sneak attack would probably be creative. The Ohio subs are supposed to be hard to track. If they are being successfully tracked then they're vulnerable to attack. The point of the nuclear triad is to be triple redundant. The system is not designed to rely solely on the ability of the subs to survive an attack. That would be a single point of failure.