And 15 years ago this week, President George H.W. Bush sent 24,000 U.S. troops to invade Panama in an attack code-named "Operation Just Cause." The attack toppled Panamanian president and former CIA asset Manuel Noriega. The exact civilian death toll from the attack is unknown. The Bush administration claimed 200 civilians had died but other estimates put the death toll as high as 3,000. Manuel Noriega remains in a US jail.