“Think about it. As bizarre as it is, this errant missile impact would give POTUS the justification to do basically anything he wanted to do in return and retaliation. Even the screaming pinkos would be relatively silent when the presidents actions were so clearly justified.”
Just shoot it out of the sky and announce the next one that launches will be shot out of the sky and we will launch one of our own in return.
That ends the problem and forces China and Russia into a game they cannot afford to play.
The problem is, current US antimissile systems are successful about 50% of the time, even when they have perfect test conditions, know the missile is coming, etc.
Are you ready to protect your home with a security system that alarms 50% of the time? Or a weapon that shoots 50% of the time?