The late Barbara Tuchman is best known for her narrative histories of both world wars and the Chinese revolution. But her 1984 book, “The March of Folly: From Troy to Vietnam,” holds special interest for Americans struggling over what to think about Iraq.

She started the book with a bang: “A phenomenon noticeable throughout history regardless of place or period is the pursuit by governments of policies contrary to their own interests.” To qualify as folly, she wrote, an action “must have been perceived as counter-productive in its own time, not merely by hindsight.” She added two other criteria: “A feasible alternative course of action must have been available.” And “the policy in question should be that of a group, not an individual ruler, and should persist beyond any one political lifetime.”

Mrs. Tuchman’s first example was the Trojan Horse, an exception to her time requirement. The ancient rulers of Troy dragged a suspicious-looking wooden horse inside their walls despite the clanking of armor inside and the warning by the priest Lacoon that it was a Greek trick. Another was George III’s successive ministries’ insistence on coercing rather than conciliating the American colonies, disregarding warnings that the harm done would be greater than any possible gain. The last of her many examples was the American 30-year involvement in the Vietnamese civil war.

Should America’s military involvement in Iraq be added to Mrs. Tuchman’s list? Not the current occupation and reconstruction, which Congress and most Americans support, on the grounds that the United States started the war that produced much of the present chaos.

But the U.S. decision to invade Iraq is more difficult. There were certainly contemporary warnings against it, notably by Germany, France and Russia. France had suffered through the quagmires of Algeria and Vietnam and warned the United States against invading Iraq.

Russia had experienced a decade-long slog in Afghanistan, and President Vladimir Putin warned recently that the United States could face a similar prolonged disaster in Iraq. He called the U.S. invasion “an error.”

Most Americans, like some allied nations, believed the Bush administration’s interpretation of intelligence to show that Iraq’s possession of nuclear bombs and other weapons of mass destruction constituted a threat to the security of the United States and other countries. History’s verdict will hinge largely on whether the U.S. search for those weapons eventually succeeds. Maine’s Sen. Susan Collins, a moderate Republican, recently told the Belfast Rotary Club: “It would be of grave importance to me if weapons are not found. That was a very important reason for my vote.”

Aside from the still-open question of the elusive weapons of mass destruction, the U.S. invasion of Iraq appears to satisfy most of Mrs. Tuchman’s criteria. There were contemporary warnings. An alternative course was available in the shape of United Nations inspections, which we now know succeeded in largely destroying Saddam Hussein’s arsenal. And while President Bush ordered the invasion, it came as the result of a long campaign by a small group of neo-conservatives, who persuaded Mr. Bush after the Sept. 11 attacks that Saddam was the key to defeating terrorism and establishing peace in the Middle East.