I can haz nukes?

This weekend I used nukes in Civ V for the first time. I was playing as the Mongol Empire on chieftain difficulty, quick speed, medium world size and an earth world type.  Since I had conquered most of Europe, all of Asia, and bits of North America and Australia, and was in a golden age, I had an income of around 800 gold/turn. With this, I bought three or four atomic bomb units and nuked the Russians quite a bit.