Note that this weakness was discovered early on. Bitcoin actually uses a sum of difficulty, not longest chain. You can't just mine more 1 difficulty blocks. But

Note that this weakness was discovered early on. Bitcoin actually uses a sum of difficulty, not longest chain. You can't just mine more 1 difficulty blocks. But your point stands, if the US Government is mining bitcoin it is plausible that they could invalidate the entire chain. I don't see everyone going with that chain.