Building up to CNN's documentary, "In the Footsteps of bin Laden," airing Aug. 23, Bergen answered questions about the mysterious al-Qaida leader.
Like Eric Rudolf, the Atlanta Centennial Olympic Park bomber, bin Laden could be close by the U.S. military, yet able to hide if he has a support network and makes no "stupid mistakes," Bergen told questioners.
Tracing financial transactions won't work if bin Laden isn't spending money. "He's lived a kind of monk-like life for a long time," Bergen said. "And he certainly isn't making cash withdrawals that can be traced."
The way the terror leader operates doesn't require much money and he may be able to live on donations, Bergen said.
The United States had its opportunity to catch bin Laden at the battle of Tora Bora, but didn't have enough troops, he said, adding Pakistan won't allow the U.S. military to go in to capture him now.
Bergen said the best way of finding him is to trace the origin of the audio and videotapes he releases, mostly to Al-Jazeera.