Monitors of Destruction

The world survived the Yellowstone mega-eruption, but not without great suffering. Extraterrestrial observers known as Monitors watched as humans, crippled with hunger and disease, bravely used cooperation and scientific process to rebuild their civilization. When attacked by an unknown species that systematically destroyed most major cities and military outposts, the Monitors decided it was time to end their eight hundred year silent observation and intercede. Monitors don't fight wars, but they will stop them.