ABOARD AIR FORCE ONE - President Bush, heading to Asia with hopes of improving his image on the world stage, hurled a parting shot at Iraq war critics on Monday, accusing some Democrats of "sending mixed signals to our troops and the enemy." "That is irresponsible," Bush said in prepared remarks he planned to deliver to U.S. forces during a refueling stop in Alaska. Excerpts from the remarks were released by the White House as Bush flew to Elemendorf Air Force Base on the initial leg of an eight-day journey to Japan, South Korea, China and Mongolia. "Reasonable people can...