Currently the US already has halfway access to the USDT which are being issued; it's centralised after all, and to some extent they determine how those USDT are being used. They order for wallets to be frozen, and the order is being obeyed.

It will be easy work for them, and I also buy the idea that if they can just abandon the CBDC shit and focus on regulating the USDT more, it will become more of the country's digital currency, but they will just implement their overprinting/minting out of thin air without proper backup.