During the year I spent at the Woodrow Wilson International Center for Scholars, I enjoyed getting to know Peter Braestrup, who had been Saigon bureau chief of the Washington Post and was the living embodiment of that pulp fiction staple, the crusty reporter with a heart of gold.

While Peter made the Wilson Quarterly an important journal of ideas, his greatest contribution to American life was Big Story, a two-volume study of the 1968 Tet offensive, the political turning-point of the Vietnam War. Alas, only two-thirds of the lessons Braestrup drew from that debacle have been learned.

Big Story demonstrated three things: 1) that the Tet offensive was a major defeat for North Vietnam and the Viet Cong; 2) that the world press badly missed the Tet story; 3) that the American people and their political leaders thought of Tet as a defeat for the U.S. and South Vietnam.

Braestrup, who died in 1997, lived to see his first and third conclusions accepted. His second conclusion --- the media botch --- has not been widely grasped, yet it's the crucial link between Conclusion One (Tet was a serious military defeat for the communists) and Conclusion Three (Tet was nevertheless a huge political victory for the military losers).

A fine review of Big Story, summarizing the book's key points, is available online at http://www.airpower.maxwell.af.mil/airchronicles/aureview/1978/nov-dec/bishop.html. In remembering my old friend Braestrup, however, the point is to look ahead, not back. For unless the American media and the American people take the second conclusion of Peter's masterpiece seriously, we may find ourselves in the morally dubious position of turning victory into defeat time and again in the war against jihadist terrorism.

Iraq is the obvious and immediate case in point. Jihadists around the world talk about the mantaq al-Madrid, the "Madrid effect," referring to the terrorist bombings of Madrid train stations that cowed Spanish voters into deposing a government that had been a U.S. ally in Iraq.

An American equivalent of the "Madrid effect" is the goal of the Saddamists and jihadists who continue to fight in Iraq, even though they know they can't possibly win --- they fight in order to degrade the political will of the American people, who are fed a steady and (rightly) disturbing diet of Iraqi chaos and mayhem by a press corps which is repeating the same mistakes in its war-reporting that Braestrup (an old-fashioned liberal) identified in his painstaking study of coverage of the Tet offensive.

As Amir Taheri has pointed out, the allied coalition that invaded Iraq had multiple goals: to depose a murderous regime, thereby ridding the world of a serious threat to international security; to empower the people of Iraq through a democratic political process; and to create a new political model for the Arab-Islamic world. The first goal was achieved, rather easily; the second goal has been largely achieved, with a constitution written, free elections held, and a legitimate government formed; and there are signs that all of this has had a leavening effect on Middle Eastern politics.

The jihadists and Saddamists who are causing mayhem (and fostering sectarian violence) in Iraq know this. Their purpose is to dismantle the success that the allied coalition and the Iraqi people have, in fact, achieved.

Reasonable people could, and did, differ about the prudence of the March 2003 invasion. My considered judgment remains that the allied action satisfied the criteria of a just war. But whatever one's position on decisions made in early 2003, surely people committed to the just war way of thinking can agree that the moral obligation to secure the peace after major combat ends --- the ius ad pacem or ius post bellum --- will not be met if the "Madrid effect" kicks in and the U.S. and its allies abandon Iraq.

That emphatically does not mean continuing failed policies. It does mean keeping focused on the legitimate, indeed noble, goal of supporting the development of a decent, self-governing society in an Iraq that could augur a better future for the Middle East.

A Tet-like victory for the jihadists will not lead to a just peace, in Iraq or anywhere else.

George Weigel is a senior fellow of the Ethics and Public Policy Center in Washington, D.C.