What if they miss?

U.S. to launch missile at broken satellite

President George W. Bush decided to make a first-of-its-kind attempt to use a missile to bring down a broken U.S. spy satellite because of the potential danger to people from its rocket fuel, officials said Thursday.
Deputy National Security Adviser James Jeffries, briefing reporters at the Defense Department, did not say when the attempted intercept would be conducted, but the satellite is expected to hit Earth during the first week of March.
He said a Navy missile known as Standard Missile 3 would be fired in an attempt to intercept the satellite just prior to it re-entering Earth's atmosphere. It would be "next to impossible" to hit the satellite after that because of atmospheric disturbances, Cartwright said.
A second goal, he said, is to directly hit the fuel tank in order to minimize the amount of fuel that returns to Earth.
Software associated with the Standard Missile 3 has been modified to enhance the chances of the missile's sensors recognizing that the satellite is its target; he noted that the missile normally is used to shoot down ballistic missiles, not satellites.

Remember the expression, what goes up must come down? So we launch the missile into the air, if it misses its target it will fall to Earth we know not where - unless it is programmed to accidently fall into Iran...