WASHINGTON — One of the Army's most Iraq-savvy generals is taking charge, at least temporarily, of arguably the most important command in the U.S. military, with responsibility for the wars in Iraq and Afghanistan. In a ceremony Friday at MacDill Air Force Base, Fla., Lt. Gen. Martin Dempsey is to assume command of U.S. Central Command from Navy Adm. William J. Fallon, who announced unexpectedly on March 11 that he was quitting. Fallon cited press reports that he was at odds with President Bush over Iran policy. Defense Secretary Robert Gates, who has denied that Fallon was out of step...