A little remembered cartoon character named Smokey Stover used to declare, "Where there's foo, there's fire." So when enigmatic aerial phenomena kept pace with airplanes and ships in both the European and Pacific theaters during World War II, someone called them "foo fighters." The name stuck. Nobody knew for sure what the foo fighters were, but it was usually assumed that the other side -- either the Allies or the Axis powers -- had developed a secret weapon. After the war's conclusion, it soon became clear that this was; not the explanation.
With the arrival of "flying saucers" in the summer of 1947, memories of foo fighters were revived. Like UFOs after them, foo fighters came in assorted shapes and descriptions, from amorphous nocturnal lights -- which gave them their name -- to silvery discs.
A typical sighting of foos took place in December 1942 over France. A Royal Air Force pilot in a Hurricane interceptor saw two lights shooting from near the ground toward his 7,000-foot cruising altitude. At first he took the lights to be tracer fire. But when they ceased ascending and followed him, mimicking every evasive maneuver he made, the pilot realized they were under someone's intelligent control. The lights, which kept an even distance from each other all the while, pursued him for some miles.
In August of that same year, Marines in the Solomon Islands were startled to see a formation of 150 "roaring" silvery objects. Their color, one witness said, was "like highly polished silver." They had neither wings nor tails and moved (as later UFO witnesses would often remark) with a slight wobble.
Official censorship kept reports of these phenomena out of the newspapers until December 1944. All during the war, however, similar objects were sighted by both military and civilian observers in the United States.