I'm talking about an attack. You might get lucky and stop 1 missile by detonating another one close to it, but you're not stopping the hundreds that would come were Russia to actually strike. Nuclear war would involve a high volume strike because destruction of the party has to be assured even before the launch. This is so known that it's actually helped avoid disaster:
Russia would not be concerned with fallout in American cities. These aren't meant to be precision strikes as much as they are to inflict mass casualties. Shooting a missile high into the atmosphere with a steep decline angle also reduces the amount of time that defense systems have to locate the missile, assess its trajectory, and try to shoot it down. Imagine this happening with hundreds of missiles, with many missiles carrying pods that could target New York City, Boston, Philadelphia, etc. out of one missile. There's no stopping that.
And that's before cruise missiles with nuclear weapons. Look how fast this shyt is moving and how close to the ground it is. There's not a way to shoot this out of the sky reliably: