In the segment broadcast, the al Qaeda leader refrained from directly threatening new attacks, although he said "there are still reasons to repeat what happened."
"Your security is not in the hands of (Democratic presidential nominee John) Kerry, (U.S. President George W.) Bush or al Qaeda. Your security is in your own hands," bin Laden said. "Any state that does not mess with our security, has naturally guaranteed its own security."
Admitting for the first time that he ordered the Sept. 11 attacks, bin Laden said he did so because of injustices against the Lebanese and Palestinians by Israel and the United States.
Bin Laden said he wanted to explain why he ordered the suicide airline hijackings that hit the World Trade Center and the Pentagon so Americans would know how to act to prevent another attack.
"To the American people, my talk is to you about the best way to avoid another Manhattan," he said. "I tell you: Security is an important element of human life and free people do not give up their security."
It was the first footage in more than a year of the fugitive al Qaeda leader, thought to be hiding in the mountains along the Pakistan-Afghanistan border. The video, broadcast on Al-Jazeera television, showed bin Laden with a long gray beard, wearing traditional white robes, a turban and a golden cloak, standing behind a table with papers and in front of a plain, brown curtain.
His hands were steady and he appeared healthy.
The Bush administration said Friday it believes the videotape was authentic and had been made recently. Bush said Friday that
The U.S. was given a copy of the bin Laden tape several hours before it aired, so intelligence analysts have had time to study it, reports CBS News National Security Correspondent David Martin. Emergency video conferences were set in motion all over Washington to assess what the tape meant and how the U.S. should react to it.
The timing of the tape suggests bin Laden is trying to influence the U.S. election -- much as the Madrid train bombings last March apparently led to the defeat of Spain's pro-U.S. prime minister, Martin reports.
One of the first things that struck analysts about the tape was bin Laden's appearance -- well groomed, well dressed, and warm, reports Martin. It was a far cry from the noticeably haggard man seen on a tape released in December of 2001. That tape spurred speculation bin Laden had been wounded in the bombing of Tora Bora. But this latest tape shows a man gesturing naturally with both hands and giving no obvious sign of disability. It puts to end any debate about whether bin Laden is alive.
A U.S. official in Washington said the entire tape was 18 minutes, lacked an explicit threat and repeated well-worn themes.
Al-Jazeera broadcast about seven minutes of the tape. The station's spokesman, Jihad Ali Ballout, said they aired what was "newsworthy and relevant" and refused to describe the unaired portions, including whether they included any threats.
Al-Jazeera, based in Qatar, did not say how it had received the tape. The channel has previously broadcast audio and video tapes from members of al Qaeda.
There was no way to determine exactly when the tape was made — but it offered evidence that bin Laden was alive and following events. Kerry emerged as the Democratic candidate in the spring.
In Florida, Kerry said all Americans are united against bin Laden, adding he would "stop at absolutely nothing to hunt down, capture or kill the terrorists wherever they are, whatever it takes, period."
Bin Laden accused President Bush of misleading Americans by saying the attack was carried out because al Qaeda "hates freedom." Bin Laden said his followers have left alone countries that do not threaten Muslims.
"We fought you because we are free ... and want to regain freedom for our nation. As you undermine our security we undermine yours," he said.
He said he was first inspired to attack the United States by the 1982 Israeli invasion of Lebanon in which towers and buildings in Beirut were destroyed in the siege of the capital.
"While I was looking at these destroyed towers in Lebanon, it sparked in my mind that the tyrant should be punished with the same and that we should destroy towers in America, so that it tastes what we taste and would be deterred from killing our children and women," he said.
"God knows that it had not occurred to our mind to attack the towers, but after our patience ran out and we saw the injustice and inflexibility of the American-Israeli alliance toward our people in Palestine and Lebanon, this came to my mind," he said.
Bin Laden suggested Bush was slow to react to the Sept. 11 attacks, giving the hijackers more time than they expected. At the time of the attacks, the president was listening to schoolchildren in Florida reading a book, an incident to which bin Laden referred.
"It never occurred to us that the commander-in-chief of the American armed forces would leave 50,000 of his citizens in the two towers to face these horrors alone," he said, referring to the number of people who worked at the World Trade Center.
In planning the attacks, bin Laden said he told Mohammed Atta, one of the hijackers, that the strikes had to be carried out "within 20 minutes before Bush and his administration noticed." Instead, bin Laden said, his operatives had three times that period.
Bin Laden also said the Bush administration was like repressive Arab regimes "in that half of them are ruled by the military and the other half are ruled by the sons of kings and presidents."
Montasser el-Zayat, a Cairo lawyer who defends Islamic radicals, said the video amounted to an "unprecedented attack on Bush at a very critical time, before the U.S. elections," and also served as proof bin Laden was alive and at large.
In elections after March 11 bombings in Spain blamed on al Qaeda, Jose Maria Aznar was defeated. The Spanish bombings came just before the vote, killed 191 people and were seen as revenge for Aznar's support of the Iraq war despite his citizens' opposition. The new Socialist leaders how defeated Aznar withdrew Spain's troops from Iraq after taking office in April.
On Web sites devoted to extremist Muslim comment, contributors reacted with glee to the tape, saying it was proof bin Laden was alive and a "slap" at America.
The image of bin Laden reading a statement was dramatically different from the few other videos of the al Qaeda leader that have emerged since the Sept. 11 attacks.
In the last videotape, issued Sept. 10, 2003, bin Laden is seen walking through rocky terrain with his top deputy Ayman al-Zawahri, both carrying automatic rifles. In a taped message issued at the same time, bin Laden praises the "great damage to the enemy" on Sept. 11 and mentions five hijackers by name.
In December 2001, the Pentagon released a videotape in which bin Laden is shown at a dinner with associates in Afghanistan on Nov. 9, 2001, saying the destruction of the Sept. 11 attacks exceeded even his "optimistic" calculations.
But in none of his previous messages, audio or video, did bin Laden directly state that he ordered the attacks.
The last audiotape purportedly from bin Laden came in April. The speaker on the tape, which CIA analysts said likely was the al Qaeda leader, offered a truce to European nations if they pull troops out of Muslim countries. The tape referred to the March 22 assassination by Israel of Hamas founder Sheik Ahmed Yassin.
Al-Zawahri, bin Laden's Egyptian deputy, has spoken on three recent audiotapes that emerged on June 11, Sept. 9 and Oct. 1 this year. In the latest, he called on young Muslims to strike the United States and its allies.