A one-world or global government is predicted in Daniel and Revelation. It will come after the rise of a confederation of ten nations or regions (Revelation 13:1; Daniel 7:16–24; Daniel 2:41–42). One member of the confederation will displace three of the other members, subdue the others, and rule over all, led by the satanically empowered Antichrist. It is this confederation of ten nations that is most often connected with the United Nations. If this connection is correct, it may be that the UN or a similar group is mentioned, indirectly, in the Bible, but there is no way to be completely sure before the Antichrist makes his appearance.
Or a line of kings/rulers... They need not be simultaneous, but only represent a time frame (in the days of these kings).
If Iran gets nukes, it will be the tenth nation to do so. Can you imagine secretary general obama demanding that the permanent seats on the security council be expanded to include all ten? I can.