Colonel, a commissioned army, air force, or marine officer ranking above a lieutenant colonel and below a brigadier general. The comparable naval rank is captain. As insignia of rank a colonel in the U.S. armed forces wears a silver eagle on each shoulder. A colonel in the U.S. Army or Marine Corps normally commands a unit larger than a battalion but smaller than a division; an Air Force colonel commands a wing. A colonel may also hold a staff office.
The film "Pearl Harbor" is now playing. Look at the aircraft involved in that battle, technological marvels for their time.
Nine countries can now deliver nuclear warheads on ballistic missiles. At least three of those countries -- the U.S., Russia and China -- could strike any target anywhere in the world. Do you know what makes a nuclear bomb so deadly?