Great. The EU works on the same principle, that's why they aren't giving the UK the terms they want. Because those other 27 member states still in the EU are still sovereign and have agreed to negotiate as a bloc. Hell, most of the antidemocratic features of the EU boil down to "the EU is accountable to member states first because member states did not surrender sovereignty when joining the union".

Y'know what we call countries who think their right to self-determination overrides others? We call them paraiahs, or war criminals if they really push the issue.