The term empire is defined here. Even though the post was written more than two years ago, I still feel like I wrote it a week or two ago.
There are no empires in the Western hemisphere.
1. China, obviously.
5. Turkmenistan (non-negligible number of Uzbeks within its territory).
6. Uzbekistan (non-negligible number of Tajiks within its territory).
9. Republic of Congo
10. Equatorial Guinea
11. Zimbabwe (the elections there are an obvious farce).
12. Ethiopia (uncompetitive elections).
13. Djibouti (uncompetitive elections).
14. Eritrea seems to be an empire, rather than the nation-state of the Eritrean people.
Belarus doesn’t count, because it is the nation-state of the Belorussian people and there’s no substantial difference between Belorussians and Russians. I haven’t heard of any Russian separatist movement in Belarus. Kazakhstan doesn’t count because it is the nation-state of the Kazakh people.
Syria would have counted before the war, but doesn’t anymore, as the Kurds have broken away. The Islamic State doesn’t count, because its ethnic cleansing has forced all those who don’t want to live under it out of its territory. Vietnam doesn’t count because the ethnic groups other than the Vietnamese are too small.
Burma isn’t an empire; it’s a mess.