Mr. Clarke is a man famously intolerant of those who disagree with him. When he cannot win the argument, he cheats. And that is what he has done again in the pages of his book. In order to explain why he opposed the war with Iraq, Mr. Clarke mischaracterizes the arguments of those of us who favored it. The key mischaracterization turns on an important intelligence debate about the identity of the mastermind of the 1993 World Trade Center bombing. This mastermind goes by the name of "Ramzi Yousef." But who was "Ramzi Yousef"?

The evidence suggests that "Ramzi Yousef" had close connections to the Iraqi security services. This evidence has impressed, among others, former CIA chief James Woolsey, and Richard Perle, former head of the Defense Policy Board. Mr. Clarke calls the Yousef-Saddam connection an "utterly discredited" theory, unworthy of serious debate. He likes the phrase so much, he even uses it on the dust jacket of his book. But let's review the facts:

• Fact No. 1: "Ramzi Yousef" entered the U.S. in September 1992 on an Iraqi passport, with stamps showing a journey beginning in Baghdad. This fact is attested by the inspector who admitted Yousef into the U.S. Yet Mr. Clarke contends that Yousef entered the U.S. without a passport.

• Fact No. 2: The sole remaining fugitive from the 1993 bombing, Abdul Rahman Yasin, is an Iraqi. After the attack, Yasin fled to Iraq. The Iraqi regime rewarded Yasin with a house and monthly stipend. Yet Mr. Clarke claims, incredibly, that the Iraqis jailed Yasin.

• Fact No. 3: Seven men were indicted in the 1993 attack. Two of the seven, Yousef and Yasin, have Iraqi connections. Yet Mr. Clarke inflates the number of participants to 12, so as to create the impression that the presence of one or two men with Iraqi connections was no big deal.

• Fact No. 4: The truth is, we don't really know much about the prisoner bearing the name "Ramzi Yousef." Judge Kevin Duffy, who presided over Yousef's two trials, observed at sentencing: "We don't even know what your real name is." Yet Mr. Clarke claims to know what the judge did not: Yousef, he writes, "was born Abdul Basit in Pakistan and grew up in Kuwait where his father worked."