Captain America Comics #70

A scientist thinks the way to ensure peace on Earth is to provide them with a giant threat so he builds a planet mover that brings Mars closer to Earth. Martians invade and nearly destroy New York City. Cap is ordered by the Martian warlord to deliver an ultimatum to the U.N., but Cap visits the lab instead and powers up the planet mover again so that Mars will return to its prior location. Since Martians can’t eat Earth food and their rockets can’t travel back to Mars, they choose to die in space. There is much rejoicing as everyone learns that you can’t get rid of evil with evil.