Assuming Chinese competitors get cut off as a "threat to national security", I'm sure Waymo would behave responsibility as a monopoly and won't be driving for a system that "accidentally" end with private car ownership being eroded along with public transport options in favour of their product.

It would be crazy if a self driving car company would undertake projects that undermine public transport, for example. Proposing mad things like vacuum pod trains to head off conventional HSR for example. Imagine!

Americans are incapable of constructing HSR all on their own. It doesn't matter if anyone tries to distract them, they'll be tied up in 200 years of lawsuits over whether the fake environment reports are long enough anyway.