If you want to know what the <span>government can do</span>, specifically, <span>you can</span> look at ... Really, two things: first, don't think that the powers listed here are the <span>government's</span> only powers.
The Aztecs lived in Mexico. That's where their empire was.
The answer to that is the Native Americans.
The bombing of Hiroshima, with about 140,000 Japanese casualties.