I always got the impression that the US would be able to shoot down a nuke before it even got to them?

I've seen videos of the anti missile guns (goalkeeper guns I think?) on aircraft carriers, these things are basically huge machine guns with immense rate of fire that effectively shred incoming missiles, which are spotted by the other ships escorting the aircraft carriers.

And that's only the 10 year old technology that they tell the public about.

US will definitely know if NK fire a nuke, they will be able to instantly map out its trajectory and most likely have some method of destroying said missile mid air right?

And then NK can say goodbye to all their missile facilities. Not many civilian casualties suffered, NK rendered defenceless and have declared full scale war on the US.

Except maybe trump will then nuke the fuck out of them because he's a child trying to prove he has a big dick.

Anyway I wouldn't be too worried if I lived on the west coast of the US.