(Another popular variant of the notion concerns the number of movie links between film actors, say between Marlon Brando and Christina Ricci or between Kevin Bacon and anyone else. If A and B appeared together in M1, and B and C appeared together in M2, then A is linked to C via these movies. A similar obsession among mathematicians involves journal articles and Paul Erdos, a prolific and peripatetic Hungarian mathematician who wrote hundreds of papers with many collaborators in a variety of mathematical areas during his long life.)
In any case, reports that the American contractor Nick Berg years ago met someone who knew accused terrorist Zacarias Moussaoui were certainly worth investigating by the FBI, but not that remarkable, especially given the intense attention focused on Moussaoui.
Many other psychological biases and illusions are illustrated by the Iraq venture. There is, for example, the "similarity bias." As social psychologists Richard Nisbett, Lee Ross, and others have shown, we're often prone to an almost magical belief that "like causes like." For this reason, for example, the lungs of a fox were thought to cure asthma, and fowl droppings were thought to eliminate ringworm, which they resemble. If two things are vaguely similar, we tend to think that acting on one somehow affects the other. So, for many, the thinking (or non-thinking) seemed to be that getting rid of Saddam would help us get rid of Osama bin Laden since they're "similar;" that is, both are Arabs and enemies.
Never mind that they hate each other.
The so-called confirmation bias also sheds some light on our involvement in Iraq. It refers to the tendency people have, once they've made even a tentative judgment, to look thereafter for factors that suggest the judgment was brilliant and ignore those that suggest otherwise. In a wide variety of contexts ranging from buying stocks to choosing colleges, people tend to look only for confirmation of what they already believe, seldom for disconfirmation. Some administration officials, for example, listened too much to ideologues and con men such as Ahmad Chalabi and not enough to diplomats and generals.
(Having mentioned links among mathematicians, I note that Chalabi has a Ph.D. in mathematics from the University of Chicago and that Deputy Secretary of Defense Paul Wolfowitz, whose father was a very eminent statistician, has an undergraduate degree in the subject. The latter fact didn't prevent Wolfowitz from publicly estimating at the end of April that the number of American military deaths in Iraq was about 500 when the reaching of that sad milestone had received much media attention in mid-January. As of this writing the number is over 800, the number wounded about six times as great. Wolfowitz might also have been expected to be more sympathetic to Lanchester's Law on troop strength.)
There are many other psychological foibles, some first pointed out by cognitive psychologists Amos Tversky and Daniel Kahneman, that are also relevant to the situation in Iraq and are a useful corrective to overweening confidence and presumption.
The physicist Richard Feynman once said, "Science is a way of trying not to fool yourself." The same might be said of competent statecraft.
Professor of mathematics at Temple University and winner of the 2003 American Association for the Advancement of Science award for the promotion of public understanding of science, John Allen Paulos is the author of several best-selling books, including Innumeracy and A Mathematician Plays the Stock Market. His Who’s Counting? column on ABCNEWS.com appears the first weekend of every month.