That's not the case though. Currently, national sovereignty doesn't really exist in this regard as most countries don't have their own national payment system.

That's not the case though. Currently, national sovereignty doesn't really exist in this regard as most countries don't have their own national payment system. Also, there already is a European system to settle transactions in Euro: TARGET2, though it is designed for use by banks and other financial institutions only. Edit: the EU becoming like 1984 is not what we should be wary of. Our societies becoming like "Brave New World" (control through hedonism instead of straightforward repression) is a much more realistic scenario.