In what was to be his last book, “The Evidence of Things Not Seen,” about the murders of black children in Atlanta in the early 1980s, the great James Baldwin had the following reminiscence:

“Some years ago, after the disappearance of civil rights workers Chaney, Goodman, and Schwirner in Mississippi, some friends of mine were dragging the river for their bodies. This one wasn’t Schwirner. This one wasn’t Goodman. This one wasn’t Chaney. Then, as Dave Dennis tells it: ‘It suddenly struck us – what difference did it make that it wasn’t them? What are these bodies doing in the river?’ “

I wouldn’t ordinarily rest anything on an assertion from the Apostle Paul, who described faith itself as “the substance of things hoped for; the evidence of things not seen.” But a whole school of pseudo-empiricism is now springing up, concerning the “evidence” from Iraq. In Slate a few weeks ago, reviewing the new book by Saddam Hussein’s one-time chief physicist, Mahdi Obeidi, I pointed to some important facts about Iraq’s weaponry that have only become known to us as a direct consequence of regime change. Some of these things – the buried nuclear centrifuge, or the attempt to purchase missiles from North Korea – were rather worse than had been previously alleged by the administration. Moreover, nobody before the war had claimed that Iraq had no covert weaponry at all. To the contrary, I used to have to argue every day with antiwar forces who said that Saddam would be able to liquidate tens of thousands of coalition troops, not to mention many Israelis, with his mighty arsenal.

A comparable elision is now under way in the matter of “terrorism.” In that Saddam will not have to stand trial for direct complicity in the crimes of September 11, 2001, it is now being freely said that he was not really a friend of jihadist fanaticism at all. The two cases in point are Abdul Rahman Yasin, a crucial member of the team that bombed the World Trade Center in 1993, and Abu Musab al-Zarqawi, currently the leader of a very deadly and ruthless group known as Monotheism and Jihad, operating in central Iraq. Mr. Zarqawi is evidently a “handson” kind of a guy: He is believed to be, and has claimed to be, the wielder of the murderer’s knife in more than one decapitation-porn video.

The latter is one respect, at least, in which he differs from Osama bin Laden. Like many a crazed Islamist, Mr. bin Laden prefers to lead from the rear and to send others to die. Even if he is still alive – which seems open to great doubt – he only escaped by running away from the capital city of the Afghanistan he had helped oppress and enslave. Not for him the baring of the chest to the Crusader-Zionist bullets. In every other important resemblance, however, Mr. Zarqawi is a bin Laden clone. He has the same theology, of contempt for Shia Muslims, Hindus, Christians, Jews, and secularists. He was in the next camp over in Afghanistan. He has been convincingly accused by the Jordanian police – he is of Jordanian nationality – of trying to get hold of chemical and biological weapons.

Ah, but is he really a certified Al Qaeda man? Well, he has made professions of fealty to Mr. bin Laden. And a Zarqawi messenger and known associate was intercepted some time ago leaving Iraq with a message for the boss about creating a new front in Iraq against all heretics and unbelievers, with special emphasis on starting a Shia-Sunni civil war. If you asked me, I would say that Mr. Zarqawi was at the very least a bin Laden wannabe, and at the very most a rival for the possibly vacant position of most lethal Islamist killer in the world. Ah, but I didn’t prove that he was actually in Mr. bin Laden’s inner circle.

An equally interesting question is Mr. Zarqawi’s connection to the Baathist underworld. It is known that he was in Iraq before the invasion, though our intelligence is so bad, yet again, that we don’t know if this was for medical treatment or not, or even whether he had lost part of a limb in or around Tora Bora. His main pre-war activity was directed at the Kurdish leadership in that part of northern Iraq that was outside Saddam Hussein’s immediate control. It is evident that he can penetrate very well guarded parts of Baghdad and other major cities, that he has more than one safe-house, and that he disposes of a huge amount of money. His network, of local and foreign recruits, is taken very seriously by all observers.

In order to believe that Mr. Zarqawi is or was innocent of Al Qaeda and Baathist ties, therefore, or in order to believe that he does not in fact represent such a tie, you must be ready to believe that:

(1) A low-level Iraqi official decided to admit a much-hunted Jordanian – a refugee from the invasion of Afghanistan, after September 11, 2001 – when even the most conservative forces in Pakistan and Saudi Arabia were keeping their distance from such people and even assisting in rounding them up.

(2) That this newly admitted immigrant felt that the most pressing need of the holy war was the assassination of Kurdish leaders opposed to the rule of Saddam Hussein.

(3) That a recently arrived Jordanian, in a totally controlled police state, was so enterprising as to swiftly put himself in possession of maps, city diagrams, large sums of cash, and a group of heavily armed fighters hitherto named after the Iraqi dictator – the Fedayeen Saddam.

I can only say that you are quite welcome to believe all of that if you wish. But you must be able to wish quite hard. The same is true of Abdul Rahman Yasin, who was at least an Iraqi passport-holder when he skipped bail from New Jersey in 1993 as one of the most wanted men in America and made it through Jordan to Baghdad in a matter of hours. Peter Boyer in The New Yorker of November 1 is the latest to see nothing especially odd in this. Mr. Boyer does concede, as the New York Times did once report, that Saddam may have hoped to use Yasin as a “bargaining chip.” Indeed. And to bargain about what? My friend Rolf Ekeus, the eminent Swedish diplomat who originally founded the Unscom inspectorate, told me that Tariq Aziz, Saddam’s slimy foreign minister, once asked him to act as intermediary. In return for an easing of sanctions, said Aziz, Iraq had a lot of information about the whereabouts of terrorists that it was willing to trade….

Millions of Iraqis can tell you that during the Saddam despotism their country was as hard to enter as it was to leave. Any reporter with average knowledge or experience can also tell you that decisions of this kind – about which high value fugitive to admit, for example – were not taken at consular or desk-officer level during the days of the supreme and absolute leader. But of course, this is no smoking gun. Perhaps, indeed, the Baathists and the jihadists simply collaborate without having to be told. Meanwhile, what are all those other bodies doing in the river?

Mr. Hitchens is a columnist for Vanity Fair.