They haven't thought this through. If the US wants to sanction country A, and country A uses a blockchain to circumvent sanctions, what do you think will happe

They haven't thought this through. If the US wants to sanction country A, and country A uses a blockchain to circumvent sanctions, what do you think will happen next? The US goes: "ah, blockchain, foiled again!!!"? Is any blockchain really resistant to country level attackers? I highly doubt that, especially against the US.