We have met the enemy, and they are us

Evil or upsetting forces exist within, not without.

Note

This is a twist on Oliver Hazard Perry's words after a naval battle: “We have met the enemy, and they are ours.” The updated version was first used in the comic strip “Pogo,” by Walt Kelly, in the 1960s and referred to the turmoil caused by the Vietnam War.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.