President Bush has eight times (someone is counting) struck the theme that the war we are in is a decisive ideological struggle. Anyone who is killed today, in Afghanistan or Iraq, will certainly subscribe to the proposition that his death was a decisive act. But we are nevertheless left wondering whether it was an ideological act, of the kind the White House is speaking of.

Ideological divisions result from irreconcilable positions held by entities laying claim to command of the scene. Mr. Bush correctly enunciates ideals that can’t be pursued in areas of the world dominated by an understanding of Islam that permits no deviation. It would not be possible to have a town meeting to elect the next mayor and board of aldermen in a town in which half of the residents were active adherents of the Taliban, the other half, Jeffersonian Democrats.

But before declaring the impasse unbridgeable, one asks: Cannot a means of living together be contrived?

In the heat of the day arrived in Washington a leading clerical figure of Iran. Mohammad Khatemi was president of Iran from 1997 to 2005 and is the highest-ranking Iranian to visit Washington since we severed relations after the 1979 revolution and the seizure of American hostages. And what does he tell us — at the National Cathedral, no less?

Well, he says, a smile on his face, we must collaborate in search of a world in which there are no extra-conventional weapons. Why should there be, when the differences between us can be dealt with other than through force and violence?

You see, he explained, there is, actually, an overlap in teachings from the three world religions that descended from Abraham.

“Jesus,” Mr. Khatemi said, “is the prophet of kindness and peace. Muhammad is the prophet of ethics, morality and grace. Moses is the prophet of dialogue and exchange.”

That doesn’t sound like Hitler talking. But overseers of the current scene aren’t interested in pacifist declamations from the mullah. What we want to hear about is the development of nuclear weapons. The Iranian government, speaking through Mr. Khatemi’s successor, President Ahmadinejad, tells the world that Iran is not engaged in developing uranium of the kind one uses to make nuclear arms. We simply have to take his word for it.

But this isn’t easy to do, and although the president of America, as the fighting chief on the western front, uses the language of apocalypse, he is criticized for doing less than what’s needed to advance our goals. Some criticisms of Mr. Bush are themselves, if not exactly ideological, certainly partisan.

Thomas Friedman, who has final thoughts on everything except his own contradictions over the years, reproaches Bush–Cheney–Rumsfeld on the grounds that they have not advocated measures consistent with an exhaustive national effort. If we are so lathered up about the Muslim menace, why have we countenanced a tax cut? Why do we let Americans burn gas, ad lib? Why aren’t we supplying the reformers in Afghanistan, and the new government in Iraq, with the kind of fighting power required to maintain the borders and guarantee stability within them?

There are very good arguments for sending more troops to Iraq and for reducing our reliance on imported oil, but these arguments have not persuaded either the commander in chief or his advisers, who believe that what needs to be accomplished can be done without gas rationing and a military draft.

What does have to happen is a softening of ideological positions. If the great fissures in the Middle East reduce to replays of old antagonisms between the Shiites and the Sunnis, we can make our modest demands, to the effect that Jesus, Moses, and Mohamed should co-exist without nuclear weapons in their portfolios. But we must also make clear that the point will one day be reached when others than America will need to be responsible for enforcing co-existence.

The challenge is to accomplish this with continued reliance on what amounts to a constabulary in Afghanistan and Iraq, because we have no appetite for great armies there, and want to believe we have no need for them.