John Negroponte is to become the deputy to US Secretary of State Condoleezza Rice.
Negroponte has a reputation for getting things done
He has been moved from his position as the first Director of National Intelligence - an office arising out of the inquiry into the 9/11 attacks, where Mr Negroponte's task was to co-ordinate several spy agencies to prevent another strike on the US.
A career diplomat, Mr Negroponte has a long history of working with the US state department, a role he greatly enjoys.
Mr Negroponte is clearly someone the president trusts - until he became the administration's man in Baghdad in July 2004, he was its representative in the United Nations, charged with arguing the case for attacking Iraq.
Picked by Kissinger
Born in London in 1939 to a Greek tycoon, Mr Negroponte was a jet-setter from the beginning, spending his childhood in Britain, Switzerland and the US.
He was educated at the elite Exeter Academy and Yale University, and went on to marry Diana Villiers, whose father was the former chairman of British Steel.
Together they have five children.
Mr Negroponte joined the foreign service in 1960, and was a rising star in the US diplomatic service, getting his first big role in Vietnam.
He learned the local language so well that Secretary of State Henry Kissinger chose him to head secret negotiations under President Richard Nixon.
Later he became ambassador to Honduras as the Reagan administration fought a covert war against the Marxist Sandinistas in neighbouring Nicaragua.
He was accused by critics of arming the Nicaraguan Contra rebels, and ignoring murder and torture by the Honduran military regime.
Later he was ambassador to Mexico and to the Philippines, before leaving the foreign service in 1996.
His record was intensely scrutinised when Mr Bush recalled him from the corporate world - as an executive vice-president for global markets with the financial services group McGraw-Hill - to take the US job at the UN.
Back then, Democratic Senator John Kerry - who later was to challenge Mr Bush for the White House - said Mr Negroponte's role in Central America should be "carefully and thoroughly examined".
Larry Birns of the Council on Hemispheric Affairs went further, calling him a Reagan "gunslinger".
But the Senate approved his appointment, and he went on to represent the US on the Security Council as Washington won international support for the war in Afghanistan in 2001.
His attempts to win a Security Council resolution explicitly sanctioning the use of force in Iraq were not successful, and the US went to war without what some saw as the only thing that would make it lawful.
But he has won praise from those with whom he has worked closely, not least the then chief of the UN.
Former Secretary General Kofi Annan said: "He's an outstanding professional, a great diplomat and a wonderful ambassador."