His car held up in a traffic jam at one of the city's many checkpoints, Ghazi al-Yawar - Iraq's interim president - loses his cool. His voice booming with anger, he orders his driver to pull out and do a U-turn into oncoming traffic. 'He's courteous except when you get him angry and then the tribal chief begins taking over,' said an aide to a member of Iraq's now-dissolved Governing Council. Described as blunt, energetic and quick-tempered, Mr Yawar, 46, is a leader of the huge Shamar tribe, which has both Shi'ite and Sunni members in Iraq and throughout the Gulf. Though a Sunni, the Shi'ite Muslims in his tribe force him to pay attention to the country's majority Islamic sect. But that strength could be a weakness. The tribal affiliations that give him a supporter base could create problems should his tribe come into conflict with another, or with the policies of the interim government. His energy, which compelled other Governing Council members to rally around him while the United States attempted to strong-arm them into selecting Adnan Pachachi, manifests itself in undiplomatic behaviour. When he was told by United Nations envoy Lakhdar Brahimi that he would not win the presidency, he stormed off, vowing to boycott the ceremony and the entire process, a governing council member said. He rang other council members and demanded they begin leaking word to the media that the US and UN were riding roughshod over the Iraqis. The fix was in, the media ran the report and, ultimately, Mr Yawar got his way. His uncle is the Shamar tribe's overall leader. A civil engineer, Mr Yawar studied at Georgetown University in Washington, as well as in Saudi Arabia, where he lived and worked as vice-president of a technology company until after Saddam Hussein's fall. Throughout his years abroad, he mostly kept his distance from opposition groups dedicated to overthrowing Hussein's regime. He was named last summer as one of the nine rotating presidents on the Iraqi Governing Council. Though tribal in his appearance and values, he's also 'a pretty modern man', said an aide to a Governing Council member, with a nationalistic rather than a tribal outlook. And he is passionate about Iraq. 'Najaf, Fallujah, Zakho, Basra, Mosul and Kirkuk are all like parts of a beautiful face,' he said in an interview last week. 'If one of these parts is disfigured, the entire face would be disfigured.'