"Justice has been done," the President said solemnly in a hastily-arranged late night TV address from the East Room of the White House. Bin Laden, he said, "murdered thousands of innocent men, women and children" and his death was "the most significant achievement to date" in the U.S. war against the al Qaeda, terrorist network that bin Laden founded, led and inspired.
After years of rumors that the world's most-wanted man was hiding in the caves and rugged redoubts of the Pakistan- Afghanistan border region, the CIA ultimately found him hiding in what officials described as a comfortable mansion surrounded by a high wall in a small town.
On Sunday, a "small team" of Americans raided the compound. After a firefight, the president said, they killed Bin Laden. No Americans were injured in the raid. Obama praised the joint efforts of U.S. and Pakistani intelligence, and appealed to Muslims around the globe to support the U.S. action.
"Bin Laden was not a Muslim leader," he said. "He was a mass murderer of Muslims."
As the first word of Bin Laden's death leaked out, a jubilant and fast-growing crowd gathered outside the White House. The throng waved flags, chanted "USA! USA!," and sang the "Star Spangled Banner."
The news came months before the tenth anniversary of the Sept. 11 attacks on the World Trade Center and the Pentagon, which were orchestrated by Al Qaeda. More than 3,000 people were killed
The horrifying attacks set off a chain of events that led the United States into wars in Afghanistan, and then Iraq. As the nation girded for more attacks, America's entire intelligence system was overhauled to counter the threat of terrorist bombs or other attacks at home.
Al Qaeda also was blamed for the 1998 bombings of two U.S. embassies in Africa that killed 231 people and the 2000 attack on the USS Cole that killed 17 American sailors in Yemen, as well as countless other plots, some successful and some foiled. It has generated local organizations in hot spots from Iraq to Afghanistan.
Panetta, the CIA director, said as recently as last summer that the United States had not obtained reliable intelligence about bin Laden's location for almost a decade.
Bin Laden first drew attention in the 1980s, when he drew on his family's vast fortune to build hospitals, mosques and other facilities to help support Afghans then fighting Soviet troops in Afghanistan. The CIA considered him a financier, not a terrorist leader.
In 1991, Bin Laden bitterly opposed the introduction of U.S. troops onto bases in Saudi Arabia during the run-up to the first Persian Gulf War, which ousted Saddam Hussein's Iraqi troops from Kuwait.
His fiery sermons demonized the Saudi rulers, and infidel Westerners, and soon attracted like-minded extremists to Al Qaeda.
The CIA has been on bin Laden's trail since the mid-1990s, when it set up a separate intelligence unit to penetrate his organization and track his whereabouts.
After the embassy bombings in 1998, the Clinton administration undertook several intelligence and military operations aimed at killing him, including one in which cruise missile attacks were ordered against al Qaeda training camps in Afghanistan. All failed.
Al Qaeda's ranks have been badly depleted in recent years and Bin Laden's death deprives the organization of its most charismatic and important leader. It leaves Ayman al Zawahri, an Egyptian physician and Islamist ideologue, as the putative leader.
Analysts said the result is likely to accelerate the fracturing of militant groups loosely associated with al Qaeda, especially in the Middle East, that have taken their inspiration from bin Laden's call for attacks on the U.S. and its allies for the more than a decade.
It was Bin Laden's fervent call for attacks on the U.S.--which he referred to as the "far enemy"--and al Qaeda's ability to recruit and train operatives from its sanctuary in Afghanistan that led to some of the world's deadliest terrorist attacks.