There are military historians who can list for you battles in recorded time in which one of the contending parties knew ahead that his side was doomed. In such cases it was sometimes necessary to fight on because there was no alternative. Genghis Khan offered zero inducements to surrender. Whether the opponent would die from the enemy's sword or his own was worth reflection, but none of it was given over to life or death: There would be death in any case.
In ensuing centuries, wars became less than final events for many soldiers, and terms of engagement changed. Robert E. Lee did not reasonably expect to be executed if he surrendered. Nor did General Lee expect, after General Sherman's march, that the South would win the war. But he fought on.
By what was he driven? Contemporary concepts of honor? It was something other than reason -- he was too skilled to have misjudged, at that point, the outcome of the war. If Hitler had known in June 1941 what would befall the German army -- and him -- in four years, he would not have invaded Russia. Four years! In four years we marched from Pearl Harbor to the heart of what was left of Tokyo and Berlin. In three years we can't yet take a cab from Baghdad to its airport without an armed guard.
Princes and generals do not communicate to the troops what are the high command's private reckonings. The matter of morale is with us in victory, and sometimes even begets victory. It also sanctifies defeat. To have died on behalf of your cause makes possible the mystic conviction that your sacrifice was the marginal contribution. To be dead at defeat permits mourning for gallantry and for faith -- My country, do or die.
President Bush will be seen commanding his troops to march on. He will speak of victory. One's guess is that there will be attenuation in the definition of victory. Three years ago (March 2003) I wrote in this space: "What Mr. Bush proposes to do is to unseat Saddam Hussein and to eliminate his investments in aggressive weaponry. We can devoutly hope that internecine tribal antagonisms will be subsumed in the fresh air of a despot removed, and that the restoration of freedom will be productive. But these concomitant developments can't be either foreseen by the United States or implemented by us. What Mr. Bush can accomplish is the removal of a regime and its infrastructure. The Iraqi people will have to take it from there."
The special challenge that Mr. Bush now faces is political. How to pull away leaving the sense of mission accomplished? He has presided over a great deal. The deposition of Saddam, his imprisonment and (never-ending) prosecution; the institution of the working rudiments of democracy. A government. And a continuing effort to train natives to take over policing the rebaptized state.
All of this is marred by shortcomings. Some observers believe them critical, enough so to conclude that the war to change Iraq's society has not been won, and cannot be won without an investment of time and resources we are not willing to make in Iraq. Other challenges loom, in North Korea and in Iran, which will tax us contingently, on a larger scale than the Saddam/Iraq war. These will need to take precedence.
Mr. Bush is entitled to maintain, doggedly and persuasively, that he took the right steps -- up through the overthrow of Saddam and the exposure of an armory without weapons of mass destruction. From that point on, the challenge required more than his deployable resources. His political reputation will rest on his success in making that point and ceding realistically to realities we are not going to cope with, and ought not to attempt to cope with.