NATO can and probably would shoot them out of the sky using ballistic missile defence. IIRC Britain has a total of 8 missiles.
Britain's obsolete Trident subs are manufactured by Lockheed, so if they fall out with Trump they will lose access to spare parts. The replacements aren't due until 2028.
Are you under some absurd notion that NATO has ballistic missile defense in Russia? Or can magically reach out and intercept a ballistic missile anywhere on the globe?
If there was the right Arleigh Burke right next to the submarine (which there wont be), and the captain was insanely paranoid enough to contravene standing rules of engagement to already be prepared for a surprise ally launching a weapon, there's about a 50% chance they could intercept each missile.
Britain's obsolete Trident subs are manufactured by Lockheed, so if they fall out with Trump they will lose access to spare parts. The replacements aren't due until 2028.