Like most of the problems the U.S. faces in Iraq, there is no solution to this one. Of course, the United States could engineer Maliki’s ouster, even without resorting to a crude coup. It need only withhold aid until the teetering government in Baghdad collapses. Perhaps merely the calls by Sens. Carl Levin (D-Mich.), Hillary Rodham Clinton (D-N.Y.) and Dianne Feinstein (D-Calif.) for Maliki to resign or be replaced by the Iraqi parliament, combined with President Bush’s tepid support, are sufficient to doom Maliki. But beware what you ask for: Maliki’s successor could well be worse. Many U.S. analysts believe the man most likely to come to power if Maliki falls is Muqtada Sadr, the radical anti-American Shiite cleric and militia leader with deep ties to Iran.