This is by WH Auden. He's my favorite poet.

Epitaph on a Tyrant
Perfection, of a kind, was what he was after,
And the poetry he invented was easy to understand;
He knew human folly like the back of his hand,
And was greatly interested in armies and fleets;
When he laughed, respectable senators burst with laughter,
And when he cried the little children died in the streets.

Also, I remembered the quote, "To save your world you asked this man to die, could he see you now would he ask why?" though I can't remember what it came from. It is something he wrote, but I can't find my poetry book right now.