Bad advice has plagued the Bush administration ever since it started planning to invade Iraq and overthrow Saddam Hussein.

Ahmad Chalabi, an Iraqi ?migr?, was a favorite early source for the Pentagon, Vice President Dick Cheney and insufficiently skeptical news reporters. Although largely discredited now, he helped persuade them that Saddam had vast stores of nuclear and biological weapons, that Saddam and al-Qaida were partners in terrorism, that the Iraqi people would welcome the American invaders.

The eminent Islam specialist Bernard Lewis, at 90, is another frequent adviser to some leading Demo-crats as well as the White House. But his belief in a secular future for Muslim and Arab countries has led him to become a cheerleader for the Iraq war and a strong influence on a Bush administration policy and strategy that are now in such a shambles.

A strikingly different analysis by a 46-year-old Iranian-American scholar, Vali Nasr, is at last attracting attention. Mr. Nasr, a professor at the Naval Postgraduate School in Monterey, Calif., argues in speeches and articles and a new book that the removal of Saddam Hussein, far from creating a liberal democracy, has “helped launch a broad Shiite revival that will upset the sectarian balance in Iraq and the Middle East for years to come.” By destroying Saddam’s minority Sunni rule, the invasion has put the majority Shiites in control, and they have brought in influence and support from Shiite Iran.

The Wall Street Journal recently reported that the Bush administration is listening to Mr. Nasr, but that his influence on U.S. policy is unclear. The influence of those who promoted the invasion seems to be waning, but top officials appear reluctant to accept such a profound criticism of their war plan.

Mr. Nasr’s latest word on the subject is an article titled “When the Shiites Rise” in the July-August issue of the journal Foreign Affairs. He suggests a way out of the present collision course in U.S.-Iran relations, with each feeling threatened by the other. He foresees a possible convergence of interests, since both want lasting stability in Iraq – Washington so it can bail out, and Iran to avoid the chaos of civil war in its back yard.

He notes that Washington and Tehran temporarily worked together after the fall of the Taliban in Afghanistan to bring the Shiites there into the political process and help stabilize the Karzai regime. He now sees a second great chance to normalize U.S.-Iran relations and enlist Tehran’s help in improving security in southern Iraq, disband-

ing the Shiite militias and persuading the Shiite parties to compromise in constitutional negotiations.

It’s advice worth listening to.