If you think that anyone can simply emigrate to the US and then just go through some straightforward process to obtain the right to vote... you may be a bit out

If you think that anyone can simply emigrate to the US and then just go through some straightforward process to obtain the right to vote... you may be a bit out of touch with how the US immigration system works these days. Further, there's been plenty of people born in and living in the US (under your definition of "a country includes any territory under its military control") who weren't able vote in US elections. There's residents of US territories who are technically citizens but cannot vote unless the migrate to the mainland. And the US has never granted voting rights to people living in countries under US military occupation.