Now, we are bound, by Treaty, to notify Russia whenever we fly a B-52, even if they are just flying to Oshkosh. The Cold War has caused us to be strategically defanged. We have sea based nukes, but those have their own limitations.
The US submarine fleet is second to none. Our technology in submarines surpass the Russians.
We can park boomers in strategic locations, and armed with multiple warheads take out multiple targets at once, within minutes of the launch order.
Mother Russia knows this, and they have a difficult time tracking or knowing our locations. And furthermore, we have attack subs roaming the seas, along with our ASW forces. The Russian technology in subs has many weak points, so finding them and tracking is not a major problem.
This sums it up on our Boomers and Attack subs if Vlad decides to start a nuke attack