Couldn't the US force use a laser, like the one they used during their demo for intercepting missiles?
The YAL-1 was a test platform mounting laser on 747. It was retired in 2014. The US is further developing airborne lasers but still working on prototype.
Possibly. But it's worth wasting a few missiles if it doesn't let the Chinese know that. Let them waste their money making a balloon armada, and if war breaks out zap them all with a laser.