Kenneth Pollack argues that the absence of a smoking gun on Iraq is not a reason to let Saddam Hussein off the hook. The preponderance of circumstantial evidence on Iraq's activities is compelling:

Former CIA analyst and national security aide Kenneth Pollack, who urges a U.S. invasion to overthrow Hussein, said reports throughout the last year alleging Iraqi ties to the Sept. 11 attacks, anthrax-laced letters and an al-Qaida enclave in northern Iraq weren't helpful.

"There's no smoking gun in any of the reports. Nobody has a smoking gun on Saddam," said Pollack, who is research director at the Saban Center for Middle East Policy with the Washington-based Brookings Institution. "But when you look at the evidence, it does start to paint a compelling picture. Any prosecutor will tell you most of his convictions are built on circumstantial evidence."