Since the letter was addressed to him directly, 60 Minutes wanted Tenet's response. Through a spokesman, he said he never saw the letter.
Former CIA European division chief Tyler Drumheller doesn't believe that. "He needs to talk to his special assistants if he didn't see it. And the fact is, he had very good special assistants. I'm sure they showed it to him. And I'm sure it was just, it wasn't what they wanted to see," Drumheller says.
The next day, Dec. 21, Tenet met with President Bush and told him making a public case that Saddam had weapons of mass destruction was "a slam dunk." Making that case would be Secretary of State Colin Powell before the United Nations. Powell sent his chief of staff, Col. Larry Wilkerson, to the CIA to prepare the presentation. Wilkerson says Tenet and his experts brought up Iraq's mobile bio-weapons program.
"They presented it in a very dynamic, dramatic, we know this is accurate way," Wilkerson tells Simon.
"Did it make any difference that the source on this was a firsthand witness?" Simon asks.
"Certainly it did. This was a man who had actually been in the belly of the beast. He had been in the lab. He had been there when an accident occurred. He'd seen people killed. And the implication was, strong implication, that they weren't killed because of the accident in the explosion, they were killed because they were contaminated. Yes, the source was very credible. As it was presented by the CIA," Wilkerson says.
Asked if Colin Powell accepted all this on blind faith, Wilkerson says, "Well, you're the secretary of state. You're not the head of intelligence for the United States. And you depend on the director of central intelligence to assimilate all the intelligence community's input and give it to you."
Once the speech was ready, Wilkerson felt the section on mobile bio-weapons was the crown jewel. "This was the strongest part of the secretary's presentation," Wilkerson recalls.
"And Secretary Powell was convinced as well?" Simon asks.
"I'm convinced he was convinced," Wilkerson replies.
On Feb. 5, 2003, Powell told the world that Saddam Hussein had mobile biological weapons. The source: Curve Ball.
"The source was an eyewitness, an Iraqi chemical engineer, who supervised one of these facilities. He actually was present during biological agent production runs. He was also at the site when an accident occurred in 1998. Twelve technicians died from exposure to biological agents," Powell said.
Prominently displayed were models of the mobile trucks Curve Ball had sketched to the Germans. The most damning evidence in the speech had come from a source no American had interviewed. Just three days later, U.N. inspectors in Iraq visited a suspected WMD location -- Djerf al Nadaf, Curve Ball's secret site. And what did they find there? A wall -- the very wall that had appeared on the overhead imagery back in 2001. Curve Ball had claimed the mobile bio-weapons trucks entered through doors at one end of a warehouse.
"When the inspectors examined the facility, they found that this was an impossibility," explains Jim Corcoran, whose job it was to relay intelligence to the inspectors in Iraq.
Corcoran learned the wall blocked any entrance to the warehouse. As for Curve Ball's hidden doors at the other end that would allow the trucks to exit?
"Again, there was a wall there, no doors. And outside there was a stone fence that would have made it impossible for this to have occurred," Corcoran says.
Corcoran knew Djerf al Nadaf was of great importance, so he sent inspectors back 20 days later to take samples, to see if any traces of biological agents were there. "They proved negative," Corcoran tells Simon. "There was nothing there."
But the inspectors' findings in Iraq made no impact; the war began three weeks later.