Thursday, June 8, 2006 Posted: 2117 GMT (0517 HKT)
Abu Musab al-Zarqawi was the man who claimed credit.
Berg's murder in 2004 was just one in a string of killings, kidnappings and suicide bombings masterminded by the "prince of al Qaeda in Iraq," a protege of Osama bin Laden.
A Sunni militant, al-Zarqawi worked to drive a wedge between the two leading Muslim religious sects and stir up violence that would hurt Iraq's fledgling democracy.
The 39-year-old Jordanian-born terrorist had eluded U.S. and Iraqi authorities for years, often mocking them with recorded messages and videotapes.
Militant Islamic Web sites quickly posted his messages, bringing terrorism to cyberspace and reinforcing his support among Islamists.
In October 2004, al-Zarqawi pledged his allegiance to al Qaeda founder Osama bin Laden, and renamed his group al Qaeda in Iraq.
With the insurgency spreading, the United States grew more determined to catch or kill the Jordanian-born militant, and increased his bounty to $25 million -- equal to bin Laden's.
"This guy, Zarqawi, has sworn his allegiance to bin Laden. He's declared his intentions," President Bush once said. "This is an enemy with no conscience, and they cannot be appeased."
Most of al Qaeda in Iraq's attacks were against Iraq's Shiite majority.
There was an upsurge in car bombings in Iraq in late April 2005 after the transitional national assembly chose a new Cabinet. It was the worst spike of attacks since the U.S.-led push against militants in Falluja the previous fall.
Al-Zarqawi sought Osama bin Laden's seal of approval, and got it. Bin Laden called him "the prince of al Qaeda in Iraq."
Al-Zarqawi's network was blamed for the 2003 suicide bombing of U.N. headquarters in Baghdad that killed Sergio Vieira de Mello, the U.N. envoy to Iraq, and 21 other people.
Counterterrorism and intelligence officials believe al-Zarqawi forged links with terrorist groups in many other countries, including his native Jordan, where he admitted to the November 11, 2005, triple hotel bombings in Amman that killed 60 people and injured scores, mostly Jordanians.
Jordanian courts have convicted and sentenced al-Zarqawi in absentia.
In December 2005, he was sentenced to death by hanging for a failed suicide bombing at the al-Karama border crossing between Jordan and Iraq. In March, he received 15 years in prison for a plot to attack the Jordanian Embassy in Iraq.
A court handed him a death sentence for the October 2002 assassination of Laurence Foley, with the U.S. Agency for International Development, and convicted him in a December 1999 "millennium" plot against Jordanian hotels.
U.S. and Iraqi forces came close to capturing al-Zarqawi several times. In December 2005, Hussain Kamal, Iraq's deputy minister of interior, admitted that Iraqi security forces had al-Zarqawi in custody in 2004, but released him because they didn't know who he was.
His luck ran out on Wednesday, when he was killed by a coalition airstrike on what was supposed to be a safe house in Baquba.
Al-Zarqawi's story began in neighboring Jordan, in the working-class city of Zarqa. The young militant, originally named Ahmad Fadil al-Khalailah, later turned the name of his hometown into an alias.
A troubled youth, al-Zarqawi drank -- a taboo in Islam. Then he found Allah, and made his way to Afghanistan in 1989 to do jihad against the Soviets. It's not clear if he ever saw combat, but when he returned to Jordan years later, his aim was clear: overthrowing the government of King Hussein in favor of an Islamic state.
Soon he was in a Jordanian prison, where he emerged as a leader among militants. Freed in an amnesty, he once again went to Afghanistan where he ran a training camp.
Al-Zarqawi fled to Iraq after the U.S.-led attack in Afghanistan and soon made a name for himself as one of the insurgent leaders.
It was after the U.S. invasion and the downfall of Saddam Hussein that al-Zarqawi emerged as a major terrorist figure in Iraq.
In February 2003, al-Zarqawi's name was mentioned on a worldwide stage for the first time, associated with Iraq, when then-Secretary of State Colin Powell appeared before the U.N. Security Council to make his case for the U.S. invasion of Iraq.
Iraq, Powell said, was harboring al-Zarqawi's terrorist network, a "collaborator of Osama bin Laden and his al Qaeda lieutenants."