Al Qaeda apparently was tightly compartmentalized; even one of Bin Laden's top spokesmen was kept out of the loop about the Sept. 11 attacks, and some of the hijackers apparently learned only at the last moment that they wouldn't be leaving the jetliners alive.
Hours after the Sept. 11 attacks, he sent a message to Hamid Mir, a Pakistani journalist who had interviewed him before, that read, "I don't have any link to the U.S. attacks, but I support it."
Later, in a statement faxed from an undisclosed hide-out, he called on Muslims in Afghanistan and neighboring Pakistan to join his holy war against the "Christian-Jewish Crusade."
In the years after the Sept. 11 attacks, Bin Laden eluded America's grasp, insulating himself within the rugged plateaus and forested mountainsides of Pakistan's tribal areas along the Afghan border and surrounded by Pashtuns who shared his opinion of the U.S..
Infighting in Washington and a lack of cooperation from Islamabad also played a role. Disagreements among Bush administration policymakers stymied plans to send Special Operations teams to track Bin Laden down. In Islamabad, the government of President Pervez Musharraf never showed any earnest desire to help.
Bin Laden might never have found refuge in Pakistan's tribal areas if it weren't for the U.S. military's ill-fated decision not to send U.S. Special Forces into Tora Bora, the labyrinthine network of caves in eastern Afghanistan where Bin Laden and Al Qaeda hid after the U.S.-led invasion in October 2001.
U.S. Gen. Tommy Franks, head of the operation in Afghanistan, gave the job of flushing out Bin Laden to a ragtag band of Afghan fighters, a move that most analysts say gave Bin Laden and his aides the opportunity to flee to Pakistan.
Rumors about Bin Laden suffering from poor health ebbed and flowed, but were never substantiated. Instead, he would periodically surface through video or audio messages that reiterated his hatred for America and its allies, and his call for Muslims join his cause. In June 2009, another purported audio message took aim at President Obama.
"Obama has followed the footsteps of his predecessor in increasing animosity toward Muslims and increasing enemy fighters and establishing long-term wars," the recording said. "So the American people should get ready to reap the fruits of what the leaders of the White House have planted throughout the coming years and decades."
Just after Sept. 11 attacks, Bin Laden issued a personal declaration of war against the United States and its allies from a man on the run who had come to believe that his faith and the Western world could not coexist.
Like President Bush, Bin Laden proclaimed that whoever was not with him was his enemy. "These events have divided the world into two camps, the camp of the faithful and the camp of the infidel," he said. "Every Muslim must rise to defend his religion."
PHOTOS: Osama bin Laden is dead
Dahlberg is a former Times staff writer.