Why Didn’t the US Shoot Down That North Korean Missile?
defenseone.com
defenseone.com
The USA and Japan (and China and Russia) likely knew within seconds that it would land in the sea and they even knew how high it would fly over a low population area in Japan.
It's like a car full of young punks stopped at a red light beside a police cruiser and when the light goes green they burn rubber and peel away from the intersection first, but never exceed the speed limit. Very provocative, but the police have real crime to deal with, so they ignore it.
The punks can be charged with dangerous driving or reckless endangerment.
Testing your ballistic missiles over populated areas is not just "provocative", it's reckless. One mistake and people die. It's not so much that it's not a "real crime", it's that [shooting the missile down / accelerating in front of the car and doing a handbrake turn into its path] doesn't make anyone safer. You deal with it afterwards.
Damaging residential communities in the japanese countryside in order to intercept unarmed missiles from NK would not be smart politics.