For several weeks, Iraq's most powerful politicians and foreign diplomats have been streaming like anxious pilgrims to western Baghdad, to the vast blue and gold dome of the Mother of All Battles mosque, which was commissioned by Saddam Hussein. They are there to visit Sheik Harith al-Dari, a 64-year-old cleric and tribal leader who has become a leading spokesman for Iraq's disaffected Sunni Arabs. Mr. Dari, a taciturn man with an air of cold authority, greets his guests in a dim office off the mosque's main hall, which is surrounded by a moat and tall minarets designed to look like Kalashnikov rifles. Then the guests get down to business. Will Mr. Dari, they ask, be willing to help bring Iraq's Sunnis into politics? Much could depend on the answer. No new government will be viewed as legitimate without the participation of the Sunni Arabs, who largely boycotted the election in January and dominate the violent insurgency here.But in a rare interview, conducted Monday through an interpreter in his office at the mosque, Mr. Dari made clear that he would continue to view the armed resistance as legitimate until the American military offered a clear timetable for its withdrawal - a condition very unlikely to be met. "We ask all wise men in the American nation to advise the administration to leave this country," he said. "It would save much blood and suffering for the Iraqi and American people." The courting of Mr. Dari is part of a broad effort to engage the Sunni Arabs, who make up a fifth of Iraq's population and supplied its ruling class under Mr. Hussein. The Shiite and Kurdish leaders who dominate the new national assembly and are now struggling to form a governing coalition say part of the delay has been caused by negotiations over which ministries should be granted to Sunnis. Reaching out to the fractious Sunnis has not been easy.