Soft Evidence

By Amanda Ripley

Americans do not need much convincing that Osama bin Laden is to blame for the attacks on Washington and New York City. Which is fortunate, because we may never have the forensic comfort of a videotape or signed contract. Clear links are almost impossible to find in shady terrorist networks designed to have none.

To make matters murkier, the U.S. government is reluctant to share any evidence it may have. On Friday, White House press secretary Ari Fleischer said publicizing evidence would compromise the investigation: "[The terrorists] would like nothing better than to be able to hide where they are hiding and have the U.S. reveal what we know and how we know it. We're just not going to do that."

While that argument makes sense from an intelligence standpoint, it may not fly diplomatically. And for now, the known case against bin Laden is circumstantial.

To be sure, the m.o. of the recent attacks basically matches that of past crimes attributed to bin Laden: i.e., suicidal followers lead quiet lives in the field, then execute an atrocity. But that model would seem to fit any anti-American terrorist group with common sense.

For now (and it's important to note that a solid investigation takes far more than a couple of weeks), the most telling evidence may be the two and three degrees separating the alleged hijackers from known bin Laden associates:

--Mohamed Atta, the suspected leader of the attack and a hijacker on American Flight 11, may have belonged to the Egyptian Islamic Jihad--a group connected to bin Laden's al-Qaeda organization--according to the FBI.

--Khalid Al-Midhar, an alleged hijacker of American Flight 77, was filmed by the CIA at a January 2000 meeting of suspected terrorists in Kuala Lumpur--an event also attended by a man linked to the bombing of the U.S.S. Cole, believed to be a bin Laden attack.

--Nabil Al-Marabh, a former Boston cabdriver arrested last week, was a friend of one of the hijackers, U.S. officials say. He also reportedly has ties to a Palestinian convicted in Jordan of planning to bomb millennium celebrations--allegedly an al-Qaeda-backed plot.

--By Amanda Ripley. With reporting by Elaine Shannon/Washington

With reporting by Elaine Shannon/Washington