i think US already Create their own crypto. what we call (xrp) ripple a US based technology company. when they first lunch this crypto theysaid xrp can kill BTC.
There is no way it will happen.
Ripple might be one of the altcoins that could give people some profit in the near future, since another fork might happen but it will never overtake Bitcoin in terms of its value and its popularity. It will stay as an altcoin, an alternative coin to Bitcoin.