“You may ask what would have prevented the enemy’s reinforcements massing and crossing the Yalu in great strength, as they had before. It was my plan as our amphibious forces moved South to spread behind us—from the Sea of Japan to the Yellow Sea—a belt of radioactive cobalt. It could have been spread from wagons, carts, trucks and planes. It is not an expensive material." - 5 Star General Douglas MacArthur