Mr Hamid Karzai was sworn in as Afghanistan's first democratically elected president this morning.
Scores of foreign dignitaries, including US Vice President Mr Dick Cheney and Defence Secretary Mr Donald Rumsfeld, gathered in the heavily fortified presidential palace in Kabul to see Mr Karzai place his hand on the Koran and take the oath.
Despite Taliban threats of violence, the capital was quiet during the inauguration.
Mr Karzai (47) was first picked by Washington to lead an interim government after US and Afghan resistance forces drove the Taliban from power in late 2001.
He has survived two assassination attempts, and US bodyguards hired and overseen by the US State Department, are in charge of his personal security.
Despite their fierce independence, the election showed most Afghans saw President Karzai as their best bet for stability after a quarter century of conflict in which warlords, communists and religious fundamentalists had all held sway.
The ethnic Pashtun must now combat Islamic extremism, disarm regional warlords and transform an economy best known as the world's largest supplier of heroin.
US policy towards Afghanistan, heavily influenced by President George W. Bush's Afghan-born ambassador to Kabul, Mr Zalmay Khalilzad, revolves around President Karzai forging some semblance of unity in a country riven by sharp ethnic divides.
How Mr Karzai juggles competition for power in his new government will go a long way to determining whether Afghans elect a pro-Karzai national assembly when they vote in parliamentary elections next April.