Terry McCarthy; Lt. General William Odom; Dr. Jerome Groopman

On the 4th anniversary of the U.S. invasion of Iraq, ABC News foreign correspondent Terry McCarthy reports on where we stand and the personal toll paid by the Iraqi people. Retired Lieutenant General William Odom shares his thoughts on President Bush's military strategy and expresses dismay about the President's idea to send another surge of troops to Iraq. Dr. Jerome Groopman shares his book, "How Doctors Think," which considers the psychology behind doctor's diagnoses.