In 1992, the Pentagon produced a controversial document, the Draft Defence Planning Guidance, which described a bold, unprecedented role for the United States after winning the cold war. The over-arching political-military strategy for the US would be to prevent the emergence of another superpower, and that the US would act to defend its interests unilaterally. There was no mention of the United Nations, with the suggestion that instead of working through the UN, the US 'should expect future coalitions to be ad hoc assemblies'. The draft was leaked and critics pounced, calling it a blueprint for US hegemony and an impossible job for the US as a 'global policeman'. But then-defence secretary Dick Cheney liked the thinking behind the document and singled out its author for commendation. That author, then an anonymous Pentagon staffer, was Zalmay Khalilzad, who this week was nominated to be the next US ambassador to the UN. Mr Khalilzad takes over from John Bolton, the cantankerous UN-hater who famously said that 'there is no such thing as the United Nations' and that if its headquarters in New York lost 10 floors, it wouldn't make any difference. When Democrats won the Congressional elections in November, it became clear that Mr Bolton - who had served 18 months without being confirmed by the Senate - would never get confirmed, and he stepped down. Mr Khalilzad is a highly regarded diplomat who also happens to be the most powerful Muslim in the US government. He received high praise for his performance as the first post-Taleban US ambassador to Afghanistan, where he was born in 1951, and then for doing the best he could with a tough assignment as the US ambassador to Iraq. But as his Pentagon past suggests, he shares an indifference towards the UN with many others in the Bush administration, tempering expectations, said Jeffrey Laurenti, a United Nations expert at The Century Foundation in New York. 'I have heard nothing particularly critical, and I have not heard any hosannas either. There was an air of relief that with Democratic control of Congress, Bolton would be leaving. But Khalilzad is not an appointment that people are particularly alarmed about or enthusiastic about,' Mr Laurenti said. He said Mr Khalilzad's thinking on the role of the US in international institutions appears not to have changed much since the notorious 1992 memo. 'There's little in his record to suggest that he's thought about the UN at all except on the ground in Afghanistan and perhaps in Iraq as well, as a tool to be used,' he said. 'That's still a big contrast with Bolton, who has thought actively about how to roll back UN influence in the world and subordinate it to US control.' Mr Khalilzad was born in Mazar-e-Sharif, in northern Afghanistan, but his family moved to Kabul before he started high school. He spent a year as an exchange student in California, and then went to the American University in Beirut. When he returned to Afghanistan after his year in California, he had changed, he told The New Yorker in 2005. 'I had different values, greater interest in sports, a more pragmatic way of looking at things, and a broader horizon. I had a sense of how backward Afghanistan was. And I became more interested in how Afghanistan needed to change,' he said. He went to graduate school at the University of Chicago and started associating with scholars who would eventually form the core of the neoconservative movement. He moved between positions in academia, think-tanks and the Pentagon, and in 1998 joined other neocons at the Project for the New American Century in an open letter to then-president Bill Clinton arguing that Saddam Hussein needed to be overthrown. But unlike many other neoconservatives, he had a pragmatic side as well. In the 1990s he did consulting work for the US oil company Unocal, which was trying to build a pipeline through Taleban-controlled Afghanistan. He met Taleban representatives when they came to Houston to visit Unocal executives, and wrote an editorial in The Washington Post in 1996 arguing that the Clinton administration should push for the Unocal pipeline, despite its misgivings about working with a government with such an atrocious human rights record. 'The Taleban does not practise the anti-US style of fundamentalism practiced by Iran - it is closer to the Saudi model,' he wrote. (In The New Yorker profile, he said the Unocal work had been blown out of proportion and that his statements critical of the Taleban from that time had been ignored.) Mr Khalilzad was still not a very high-level official on September 11, 2001, but his intellectual credentials and his Afghan heritage thrust him into prominence. Mr Bush picked him to be the post-war ambassador in Kabul, and he became so close to Afghanistan President Hamid Karzai that when word came that he was to move to Baghdad, Mr Karzai personally asked Mr Bush several times to change his mind. In Iraq, Mr Khalilzad received good marks for his political instincts, said Juan Cole, a professor of history at the University of Michigan and a prominent commentator on Iraq. 'Khalilzad was the first US ambassador to post-Baath Iraq who really knew something serious about Middle Eastern culture and politics,' Professor Cole said. 'He worked very hard to bring the Sunni Arabs into the political process and had some successes in that regard.' Mr Khalilzad took part in the effort to get rid of Iraq's first post-Saddam prime minister, Ibrahim Jaafari, and suffered the wrath of many Shiites, who thought that he, as a Sunni, was biased against them. 'But the main problem he faced was that he could really only affect politics at the parliamentary and government level inside the Green Zone,' Professor Cole said. Over the last year, as sectarian violence has got worse and worse, 'the main action shifted to the street', he said. 'Death squads, kidnappings, reprisal killings so poisoned the political atmosphere that ultimately Khalilzad's attempts to craft nuanced political compromises among the high politicians increasingly seemed irrelevant.' So Mr Bush tapped him for another thankless job: representing the US at the UN. Mr Laurenti said: 'What he would bring to the UN, they [in the Bush administration] might imagine, is for the first time a Muslim face, in a place where the distemper of the Muslim world towards American policy and dominance is often very sharply expressed.' Mr Khalilzad's natural interest is in political and security issues, the kinds of things dealt with in the Security Council - but Washington usually deals with those matters outside the auspices of the UN, Mr Laurenti noted, which will probably mute Mr Khalilzad's impact. Where he may be able to make more of a splash is in the General Assembly. 'You have issues about democracy and human rights that recur often in the General Assembly and I think this may be a place where his skills at building a larger coalition will be tested,' Mr Laurenti said. As with Iraq, though, bringing the US back into the world's good graces may be too tough a job even for Mr Khalilzad, said David Shorr, of US think-tank Stanley Foundation. Mr Khalilzad 'is a highly capable policymaker and diplomat, and at the UN, the job he is taking could do a lot to bring the US and the rest of the world closer together', Mr Shorr said. 'He can't do that singlehandedly, though, and the UN is just a part of that challenge.'