61% is absurdly optimistic, no doubt quoted from a contractor who constructed a CDR acceptance test to be successful.
I have not seen the film. I presume the incoming missile was not MIRVed? The trailers look absurd.
There is no defense against ICBMs. There is even less defense against SLBMs. We park 80% of our warheads on subs for this reason. The Russkies park 60%. They can be more flexible because their ICBMs are mobile and can move and be missed. Ours are in fixed silos.
This is why bombers are largely insignificant for nuclear exchange. The war is over by the time they arrive with their very few warheads.
Who is the supposed attacker in the trailer? A rogue element would not have MIRV missiles