> So you're saying that the laws under which Americans are governed shouldn't be up to Americans but should be, at least for some things, up to people who live in other countries?

No, I'm not making any normative statement about what laws should be. I'm pointing out a fairly direct reading of the plain language actually adopted in the 8th Amendment. Which, in any case, was drafted and ratified by Americans, and so, whatever interpretation of it is correct, is not an example of the law under which Americans are governed being up to anyone but Americans.