In the history of art it comes in every form, from intimate, stable scenes to teeming Busby Berkeley spectacles with squadrons of formation-flying angels. "There is a marked difference between Protestant introspection and Catholic display," says Charles Saumarez Smith, the National Gallery's director.

In less elevated terms, it comes conveniently packaged for the modern home, with winking lights and nodding donkeys: singing, dancing, ethnic, edible, inflatable, not to say theologically confused.

On the internet you can buy cribs at which Mary welcomes Father Christmas and a penguin to the manger; the Holy Family look worryingly like the Flintstones; or the baby Jesus is a sort of Eucharistic truffle, robed in chocolate with a vin santo filling.

To begin with, it's odd that just two of the four Gospels have anything to say about the Nativity. Mark and John offer no comment at all.

Only Matthew and Luke, both written 60-70 years after Jesus's death, give the story.

And, according to Geza Vermes, Emeritus Professor of Jewish Studies at Oxford and author of a recently published study, The Nativity, it isn't even the same story.

"In our traditional understanding Matthew and Luke are nicely fitted together and their contradictions ignored," says Vermes. "But what they say is totally different. And what's more, it appears nowhere else in the New Testament. No repetition. No reference. From which I conclude that it's a secondary addition: a splendid prologue to the life of Jesus supplied by men who had a reason to supply it."

For Matthew, a Jew writing for Jews, the objective was to show how Jesus's birth fulfilled the prophesies of the Torah. For Luke, a gentile writing for gentiles, the objective was to explain Jesus in terms that a pagan audience reared on myths of gods impregnating mortals would understand.

… The Virgin Mary is actually called Miriam - she was Jewish, after all - and her virginal status is important to Luke because it fits the Classical image of maidens begetting divine children.

Whereas Matthew has the details of the birth revealed to Joseph in a dream, Luke has an Annunciation made to Mary by an angel. Western painters stress her detachment from the mess of birth by showing her in seated composure.

Painters of Eastern icons let her lie down. And nowhere does The Bible tell us she wears blue. Her wardrobe largely derives from medieval meditations and visionary experiences, such as those of St Bridget, who had a keen eye for detail.

Joseph is usually depicted as a bit-part actor in the drama and as old, although The Bible does not indicate his age. Some pictorial traditions make him a comic figure and certain cathedrals had a vested interest in adding homely details - notably Aachen, which became the proud possessor of St Joseph's stockings, which had been cut up to make clothes for the infant Jesus. Jesus In paintings, he is usually depicted naked with what would these days be thought an unseemly attention to his penis.

… The Three Kings - only Matthew mentions them. He doesn't call them kings. And he doesn't say how many there are. The earliest nativity scenes show just two, and their number and status were upgraded later, on the grounds that there were three gifts, one of which was frankincense, associated with royalty.

More practically, though, the upgrading of the kings was also connected with the church's desire to allot a role in Christian life to rich potentates (who would otherwise be struggling through the eyes of needles) and get their money.

The kings also symbolized the universal outreach of the Church, to Europe, Africa and Asia. And again, certain cathedrals had a special interest in them: Cologne claimed their bodies and declared them to have died at the respective ages of 109, 112 and 116.

The Ox and Ass There is no mention of them in the Gospels. But if Jesus was born in a stable it would be reasonable to assume their presence. And the first person to make a point of it was St Francis, who is said to have begun the tradition of cribs and nativity re-enactments in the 13th century.

The Shepherds are found only in Luke. Important as a statement of the access ordinary people have to Jesus.

The Star in Matthew but not Luke, and the subject of endless debate as to what, if anything, it might have been. There is no unchallengeable recorded evidence of starry phenomena around this time.

Few clerics I approached - including the Archbishops of Canterbury and Westminster - were prepared to risk a comment. Of those who were, the most forthright was the director of the Catholic Agency for the Support of Evangelism, Mgr Keith Barltrop, who agreed that "Matthew and Luke put their Gospels together in a certain way to make certain points, but a Catholic would believe them to be based on history and essentially true. At the end of the day, it's a matter of faith."

Almost as forthright was the Rt Rev Richard Chartres, Bishop of London, who complains that 'our modern minds want photographic evidence: someone at the cribside with a Polaroid to show us what we see on Christmas cards … Well, nobody was there with a Polaroid, and the gospel narratives don't work like that. They don't inform us. They initiate us into an awareness, a way of seeing and being, and that's the way the early church would have understood them."

The most apposite demonstration of our celebrity-obsessed times must surely be Madame Tussauds' Nativity scene of 2004.

The waxwork depicted Victoria and David Beckham as Mary and Joseph with Kylie Minogue as a pert-buttocked Angel of the Annunciation, and - contentiously - President Bush, the Duke of Edinburgh and Tony Blair as the Three Wise Men.

The scene was criticized as both a new low in the cult of celebrity worship and preposterous blasphemy. The display was open for only a few days before James Anstice, a religious protester, decapitated Posh and knocked over Becks on the grounds of 'waging a war against crap'.

Anstice appears to be fighting an unwinnable war. For instance, the Our Lady of the Snows church in Belleville, Illinois, last year displayed a life-size Nativity scene made from Lego.

Kitsch abounds even in Naples, the world capital of Nativity scenes since the 18th century, when the Bourbon king Charles III ordered them to be made there. Today, countless artisans in the city's Old District work all year to construct presepi. For every exquisite, hand-carved Madonna and Joseph, there's a 25-piece scene made entirely out of dried pasta.

The Radio City Christmas Spectacular, which has played annually at New York's Rockefeller Center since 1933, is a fine example. More than a million visitors witness this gaudy extravaganza of high-kick dance numbers and skating routines, culminating in the 'Living Nativity' play, for which the vast stage becomes a desert that Mary and Joseph - with live camels, sheep and donkeys for company - cross in search of an inn.

For instance, www.stpatricksguild.com offers a Nativity Bake Set, which allows you to recreate the manger scene out of gingerbread and cookies; an Outdoor Inflatable Nativity, a 9ft tall display with self-inflating, biblical figures; and, most interestingly of all, a Kneeling Santa, a wooden figurine of Father Christmas humbly, if incongruously, kneeling at Baby Jesus's crib.

In 632, after five years of fearful warfare, the city of Mecca in the Arabian Hijaz voluntarily opened its gates to the Muslim army. No blood was shed and nobody was forced to convert to Islam, but the Prophet Muhammad ordered the destruction of all idols and icons of the Divine. There were a number of frescoes painted on the inner walls of the Kabah, the ancient granite shrine in the centre of Mecca, and one of them, it is said, depicted Mary and the infant Jesus. Immediately Muhammad covered it reverently with his cloak, ordering all the other pictures to be destroyed except that one.

This story may surprise people in the west, who have regarded Islam as the implacable enemy of Christianity ever since the crusades, but it is salutary to recall it during the Christmas season when we are surrounded by similar images of the Virgin and Child. It reminds us that the so-called clash of civilizations was by no means inevitable. For centuries Muslims cherished the figure of Jesus, who is honored in the Qur'an as one of the greatest of the prophets and, in the formative years of Islam, became a constituent part of the emergent Muslim identity.

… The Qur'an is horrified by Christian claims that Jesus was the "son of God", and depicts Jesus ardently denying his divinity in an attempt to "cleanse" himself of these blasphemous projections. Time and again the Qur'an insists that, like Muhammad himself, Jesus was a perfectly ordinary human being and that the Christians have entirely misunderstood their own scriptures. But it concedes that the most learned and faithful Christians - especially monks and priests - did not believe that Jesus was divine; of all God's worshippers, they were closest to the Muslims (5:85-86).

… The Qur'an insists that all rightly guided religions come from God, and Muslims are required to believe in the revelations of every single one of God's messengers: "Abraham and Ishmael and Isaac and Jacob ... and all the other prophets: we make no distinction between any of them" (3:84). But Jesus - also called the Messiah, the Word and the Spirit - had special status.

Jesus, it was felt, had an affinity with Muhammad, and had predicted his coming (61:6), just as the Hebrew prophets were believed by Christians to have foretold the coming of Christ. The Qur'an, possibly influenced by Docetic Christianity, denied that Jesus had been crucified, but saw his ascension into heaven as the triumphant affirmation of his prophethood. In a similar way, Muhammad had once mystically ascended to the Throne of God. Jesus would also play a prominent role beside Muhammad in the eschatological drama of the last days.

I heard the bells on Christmas Day
Their old familiar carols play.
And wild and sweet the words repeat
Of Peace on earth, good will to men.

I thought how as the day had come
The belfries of all Christendom
Had roll'd along th' unbroken song
Of Peace on earth, good will to men.

And in despair, I bow'd my head:
"There is no peace on earth," I said,
"For hate is strong and mocks the song,
Of Peace on earth, good will to men."

Then from each black, accursed mouth
The cannon thundered in the South,
And with the sound the carols drowned
Of peace on earth, good will to men.

It was as if an earthquake rent
The hearthstones of a continent,
And made forlorn, the households born
Of peace on earth, good will to men.

Then pealed the bells more loud and deep;
"God is not dead, nor doth He sleep;
The wrong shall fail, the right prevail,
With Peace on earth, good will to men."

I was walking across Central Park on my way to Bible-study class around 8:30 Saturday morning - take that, Red States - thinking about God's role in history. Long story short: I think it's zip, nada, null set, etc. Why? Look at Ahmet Ertegun. What kind of God would have killed him BEFORE the Stones show at the Beacon, rather than after? OK, look at the Holocaust, Cambodia, AIDS in Africa, honor killings for Islamic homosexuals, George W. Bush being the leader of the most powerful nation in human history, half the world living on less than $2 a day ... etc. Is there any justice on this earth? The only possible answer can be: Not that any of us can figure out. And if God is just (and merciful) then clearly, he's not around, or not interested, or non-existent. I don't profess to know whether God exists - personally I think so, because I believe in a kind of intelligent design as the source of the order of the universe - but that is, I think, as far as it goes. What's the upshot of all this deep thinking? Just this: If someone, say, George W. Bush, tells me that he is doing something or has done something because God willed it, I'd tell him to fuck off. Nobody knows God's will or can explain why the universe operates the way it does if the spirit they follow is, in fact, a benevolent one. (And if it's not, well, then it should be resisted as forcefully as possible.) In any case, most of the people throughout history who claim to know God's will have tended to get a lot of the rest of us killed, burnt, raped, tortured, pillaged, thrown out of planes and the like. The crucial distinction in political culture in the world today is between God and the Enlightenment; that is imposed theology or reason. Bush, Osama, Pat Robertson, and Fidel Castro are all on one side of this argument. (Marxism/Leninism is an ideological form of "God.") Those of us who think for ourselves are on the other. I'm all in favor of "religion in politics." This is after all, a religious country, and the most popular religion - Christianity - happens to be on my side in most things. Just don't tell me you know what "God" thinks about anything. You don't. For all you know, he thinks you should go to hell.

Thanks so much for sharing your religious views. My, in such mine fields you choose to tread!

But, no, I don't believe He gives a flying whatever about our "history" nor does He play a significant role. He does not come down here (I think, down) and visit miracles upon us in violation of His own natural laws. The maladies we suffer we bring entirely upon ourselves, i.e., the election of Mr. Bush or the selection of John Kerry.

For Him to interject Himself in these processes would undermine the concepts of intellect and free will. We can neither blame Him for our predicaments nor credit Him with the solutions. It is for us to use His gifts to figure it out for ourselves.

The unholy right wing in this country has chosen to inject God into our public debate from time to time and it has cost them votes, including mine. I have had many of my friends come to call themselves "conservative democrats until these idiots get out of my bedroom!"

I believe you have nailed the lunatic right wing in this country. But, be careful. On the same page you claim "moral superiority." Too tempting to go there, was it not?

Appreciate your courage.

From the ever shrinking Red States, DR

Speaking of God, Eric, isn't it telling that no one who claims to know God's will or hear God's voice ever hears the Almighty say, "No, no, no don't do that. For My sake, please don't do that."

The sheer improbability of Ahmet Ertegun's career makes it an all-American success story: the tale of an outsider, from Turkey no less, who loved African American music so much that he became a major force in pop history. Points of friction in American culture - class, ethnicity, race, religion - mostly provided him with sparks.

Ertegun, who died on Dec. 14 at 83, was an old-school music mogul, a self-invented character with the urge to start a record company. He was, by all accounts, a charmer: a man of wealth and taste who had stories to tell, a shrewd business sense and a keen appreciation of all sorts of pleasure. He wasn't a musician, but he had an ear for a hit, one that served him for half a century.

When Ertegun and a partner floated Atlantic Records in 1947 with a $10,000 loan from a dentist, it was one among many small independent labels trying to serve the taste of postwar America. But while the others had their handfuls of hit singles and disappeared, Atlantic kept growing. With Ertegun as chairman, the job he held until his death, it was a major label by the 1960s, the home of multimillion sellers like Led Zeppelin and the Rolling Stones in the 1970s and the core of the Warner Music conglomerate that continues to survive in the currently embattled recording business.

David Geffen, an entertainment mogul, said Friday that he had once asked Ertegun how to make money in the music business. Ertegun said he would demonstrate, got up from his chair, hunched over and shuffled slowly across the room. Geffen didn't understand, so Ertegun did it twice more. Finally he explained: "'If you're lucky, you bump into a genius, and a genius will make you rich in the music business,'" Geffen recalled. "Ahmet bumped into an awful lot of geniuses."

Geopolitically, the resurgence of religion is dangerous and spreading. From Islamic fundamentalism, American evangelism to Hindu nationalism, each creed demands total conformity and absolute submission to their own particular variant of God's revelation.

Common to virtually all versions of contemporary religious fanaticism is a claim to know divine intention directly, absolutely and unquestionably. As a result, many people demand a fresh liberal resistance to religious totalitarianism.

But it is important to realize that this reduction of a transcendent religion to confirmation of one's own personal beliefs represents an ersatz copy of liberal humanism. Long before religious fundamentalism, secular humanists reduced all objective codes to subjective assertion by making man the measure of all things and erasing God from nature.

This was a profoundly secular move: It simply denied natural knowledge of God and thereby eliminated theology from the sciences. Religion, stripped of rationality, became associated with a blind unmediated faith - precisely the mark of fanaticism. Thus religious fundamentalism constitutes an absence of religion that only true religion can correct.

Darwinism is close to being completely rewritten. Hitherto, it had been assumed that forms of life are the product of essentially arbitrary processes, such that (as Stephen Jay Gould put it) if we ran evolution again life would look very different. However, evolution shows biological convergence. As Simon Conway Morris, a professor of biology at Cambridge University, has argued, evolution is not arbitrary: If it ran again, the world would look much as it already does.

Nor is natural selection now thought to be the main driver of biological change. Rather, life displays certain inherency, such that the beings that come about are a product of their own integral insistence. All of which means that there is no necessary conflict between evolution and theology. Indeed, evolution is no more arbitrary than God is deterministic. Similarly, in cosmology and physics the idea that the world was produced by chance has long been dismissed. The extreme precision of the gravitational constant that allows a universe like ours to exist requires an explanation. Rather than envisioning the world as an intended creation, secular physics posits infinite numbers of multiverses existing alongside our own. Thus, the sheer uniqueness of our universe is qualified by the existence of all other possible universes.

The trouble is that this supposition sounds more bizarre than religion. Moreover, to posit this paradigm leads to the Matrix hypothesis that we are actually only a virtual simulation run by other universes more powerful and real. So religion finds itself in the strange position of defending the real world against those who would make us merely virtual phenomena.

Philosophically, if one wants to defend the idea of objective moral truths, it appears ineluctably to require some sort of engagement with theology. For if there are universals out there, we need to explain why they care about us or indeed how we can know them at all. And if human beings do not make these truths, then it seems an account of the relationship between ultimate truths and human life can only be religious.

More American college students seem to be practicing traditional forms of religion today than at any time in my 30 years of teaching.

At first glance, the flourishing of religion on campuses seems to reverse trends long criticized by conservatives under the rubric of "political correctness." But, in truth, something else is occurring. Once again, right and left have become mirror images of each other; religious correctness is simply the latest version of political correctness. Indeed, it seems the more religious students become, the less willing they are to engage in critical reflection about faith.

The chilling effect of these attitudes was brought home to me two years ago when an administrator at a university where I was then teaching called me into his office. A student had claimed that I had attacked his faith because I had urged him to consider whether Nietzsche's analysis of religion undermines belief in absolutes. The administrator insisted that I apologize to the student. (I refused.)

My experience was not unique. Today, professors invite harassment or worse by including "unacceptable" books on their syllabuses or by studying religious ideas and practices in ways deemed improper by religiously correct students.

Distinguished scholars at several major U.S. universities have been condemned, even subjected to death threats, for proposing psychological, sociological or anthropological interpretations of religious texts. In the most egregious cases, defenders of the faith insist that only true believers are qualified to teach their religious tradition.

For years, I have begun my classes by telling students that if they are not more confused and uncertain at the end of the course than they were at the beginning, I will have failed. A growing number of religiously correct students consider this challenge a direct assault on their faith. Yet the task of thinking and teaching, especially in an age of emergent fundamentalisms, is to cultivate a faith in doubt that calls into question every certainty.

Since religion is often most influential where it is least obvious, it is imperative to examine both its manifest and latent dimensions. As defenders of a faith become more reflective about their own beliefs, they begin to understand that religion can serve not only to provide answers that render life more secure but also to prepare them for life's unavoidable complexities and uncertainties.

Until recently, many influential analysts argued that religion, a vestige of an earlier stage of human development, would wither away as people became more sophisticated and rational. Obviously, things have not turned out that way. Indeed, the 21st century will be dominated by religion in ways that were inconceivable just a few years ago. Religious conflict will be less a matter of struggles between belief and unbelief than of clashes between believers who make room for doubt and those who do not.

The warning signs are clear: Unless we establish a genuine dialogue within and among all kinds of belief, ranging from religious fundamentalism to secular dogmatism, the conflicts of the future will probably be even more deadly.

Conservative distrust of the media's very real bias has inclined us to dismiss reports about problems in Iraq that are real.

In the end, I think the media bears fundamental responsibility for this. Had they been less biased - had they reported acts of heroism and the many good things we have done in Iraq - I think conservatives would actually have taken their reporting of the problems in Iraq more seriously. In effect, the media's consistent liberal bias discredits even its valid reports.

... It's a terrible shame that we've come to the point where our ability to believe news reports hinges on a those rare cases where the record shows freedom from liberal bias. The media has discredited themselves, making it tough to take them seriously even when they are right, and that has hurt us all.

Why is this suddenly so popular? The argument carries a lot of wingnut water. First, it emphasizes that the problem in Iraq is that we've been too soft, and suggests that a more hard-line, brutal approach would put the natives in line. Second, it places implicit blame for the problem not on the people who actually designed the rules (the Army, Marine Corps, DOD, and the Bush Administration), but on those who we already know are soft and weak and don't care about American soldiers. Thus, the problem is defined as "Politically Correct Rules of Engagement", suggesting that the villains are likely liberals, Clintonistas, UN-niks, etc. Third, it allows wingnuts to express concern for the well being of the troops in the field, while ignoring the fact that the troops would be much, much safer if they weren't in Iraq, regardless of the ROE.

President Bush's tortured grasp of the English language is legendary, but I submit that during this morning's presser he actually provided an important clue to understanding what it is he's been saying about Iraq. He is speaking in a new tense that the rest of us have thus far failed to note the existence of: the fantasy tense.

Q - Mr. President, less than two months ago at the end of one of the bloodiest months in the war, you said, "Absolutely we're winning." Yesterday you said, "We're not winning, we're not losing." Why did you drop your confident assertion about winning?

THE PRESIDENT: My comments - the first comment was done in this spirit: I believe that we're going to win; I believe that - and by the way, if I didn't think that, I wouldn't have our troops there. That's what you got to know. We're going to succeed. My comments yesterday reflected the fact that we're not succeeding nearly as fast as I wanted when I said it at the time, and that conditions are tough in Iraq, particularly in Baghdad.

Bush could easily have used the future tense and said, "we will win." Or he could have used an imperative construction: "we must win." But he didn't. He used the present tense and now says that his use of the present tense should merely be understood to mean what "I wanted" and what "I believe that we're going to."

Thus, the present tense when used by Bush lacks its traditional meaning and should be understood, according to the president himself, only as an expression of his desires and beliefs. In short, he is speaking in something that must be understood as "the fantasy tense." The "I believe/I want/I hope this happens" aspect just happens to be implicit, making the tense sometimes hard to recognize.

• "We began the year with optimism after watching nearly 12 million Iraqis go to the polls to vote for a unity government and a free future. The enemies of liberty responded fiercely to this advance of freedom."
• "And I want the enemy to understand that this is a tough task, but they can't run us out of the Middle East; that they can't intimidate America."
• "What is going to happen is we're going to develop a strategy that helps the Iraqis achieve the objective that the 12 million people want them to achieve, which is a government that can - a country that can sustain itself, govern itself, defend itself."
• "A free country that will serve as an ally in this war against extremists and radicals."

• We're in Iraq to build a democracy.
• No, we're in Iraq to find a permanent base for US military forces in the Middle East or, at a minimum, to demonstrate resolve detached from specific policy goals.
• No, we're in Iraq to build an internally stable government.
• No, we're in Iraq to create a government that will take America's side in regional disputes.

Needless to say these are different and, in some ways, contradictory goals. This is why we're not winning in Iraq and never will. We don't have coherent objectives we're pursuing. And there is no set of objectives such that the objectives are both achievable and worth the cost of achieving them. The sane thing to do at this point is to set a goal of removing American troops from the killing zone quickly and then to start thinking and arguing about how, exactly, this can be done in a way that minimizes risks to the troops and the rest of the region.

At his press conference Wednesday, the president was asked what lessons he's learned after five years of war. He's been asked a version of this question many times since he had such trouble answering it in April 2004. He has tried various responses over the years and none has been satisfying. This morning's answer also fell short: "It is important for us to be successful going forward is to analyze that which went wrong, and clearly, one aspect of this war that has not gone right is the sectarian violence inside Baghdad." [Yes, the sentence structure is odd - AMP]

It is progress of a kind for the president to talk about the need to examine past failures - there was a time when he didn't even admit them - but the answer still failed. First, Bush didn't actually answer the question. He talked about what went wrong, but not what he learned. Second, Bush seemed to suggest that the sectarian violence in Iraq was unforeseen - not so much something that went wrong, but a surprise they didn't anticipate. But war planners did know the sectarian violence was coming. The State Department, Army War College, and CIA analysts all predicted that the Shi'a and Sunnis would go after each other (apparently they've been at it for a while). The president and his team ignored or discounted these assessments.

It's hardly surprising that the president didn't answer a question at a press conference. Bush regularly answers the wrong question at length to give the appearance of answering without actually doing so. He gives a response when what we want is an answer.

People don't trust the president on the war, and they don't approve of the job he's doing. They haven't for a long time. They think he's either lying to them or that he's out of it. The tricks he has offered to win them back to his strategy - from scaring the public about Democrats and their proposals, to hyping the consequences of not following his policies, to poking his finger in the air - have not worked. This is a problem for him, because in January he will give yet another Big Speech on Iraq. In it he will offer his new strategy for completing the mission.

But why will anyone listen to Bush's new approach?

First, Bush's people are trying to show that the president is working really hard to find the new answer. He has ordered reviews at the State Department and Pentagon and held repeated meetings with military officials. He's also studying the Iraq Study Group plan (even though he has pretty much trashed its major recommendations). Second, the president and his aides are trying to show that he actually understands how grave the situation is in Iraq. On Tuesday, he told the Washington Post that America is not winning in Iraq, matching the candor for which his incoming secretary of defense was praised during his confirmation hearings.

To get people to buy into his solutions, the president has to put candor into his policy review. He has to prove that the new solutions weren't cooked up with the same broken process that cooked up the first batch of bad solutions. Which brings us back to the question of what lessons he's learned. He's been accused to living in a bubble, so who told him things during this round of meetings that he didn't want to hear? Whom did he seek out at the State Department that he would not have in the past? Who yelled at him? Who talked him out of a bad idea? What gut instinct that he trusted in the past has he learned to think twice about? He should answer the question about what he's learned from his mistakes, how he incorporated those lessons into his new policy process, and how the strategy he's put forward is the fruit of that new way of operating. That might - might - persuade some Americans to give him one more chance.

It proposes "surging" 20,000 extra troops to secure Baghdad as a necessary and sufficient first step to securing and rebuilding the whole country.

It's being taken very seriously in White House and congressional quarters. I don't understand why, because it's not really a serious study. Numbers are grabbed out of thin air. Crucial points are asserted, not argued. Assumptions are based on crossed fingers, not evidence or analysis.

The upshot is that Kagan's surge involves more troops than the United States can readily mobilize and fewer troops than it needs for the kind of victory he has in mind.

He proposes a classic "clear and hold" method to secure the capital. Troops sweep into Baghdad's nastier neighborhoods and clear them of insurgents and other bad guys. Some troops stay behind to maintain security, while others move on to clear the next set of neighborhoods; some of those stay behind, while others move on; and so forth. Once Baghdad is stabilized, still more troops will pour into other troubled cities. Meanwhile, security allows reconstruction to proceed.

However they're counted, a lot of extra troops are necessary, because not only do they have to "clear" a neighborhood of bad guys, some have to stay there ("hold" the area) while others move on to clear the next neighborhood. (This was the problem at Tal Afar. The city was cleared, but then the troops were called to Baghdad, and the insurgents returned.)

In Kagan's plan, after Baghdad is secure, we have to go clear and hold the rest of Iraq. This means still more troops will be needed, beyond the initial surge, because the troops in Baghdad have to stay there.

Where will these troops come from? Kagan says that the Pentagon will have to expand the size of the Army and Marines by at least 30,000 a year over the next two years. However, according to some very high-ranking officers who deal firsthand with these sorts of issues, the Army can recruit, train, and equip only about 7,000 combat troops a year. This is a physical limit, constrained by the number of bases, trainers, supplies, and other elements of infrastructure.

Kagan writes, "The President must call for young Americans to volunteer to defend the nation in a time of crisis." Given the unpopularity of the president, and of this war, this seems unlikely. After the Sept. 11 attacks, when Bush was at peak popularity, and when the country was experiencing a surge of patriotism, Congress passed a bill expanding the size of the Army by 30,000 troops. Five years later, the Army has actually expanded by just 23,000 troops. It's still 7,000 troops short of that target. How does Kagan expect to attract 30,000 more in just one year, much less to do so two years in a row?

… if Kagan's advice is followed, the surged troops will have plenty on their hands. Kagan writes that they will have to fight the bad guys - and provide food, water, electricity, and other essential services. It's not as if they haven't been trying to do all that for the past three and a half years.

How long will the surged troops have to stay? Kagan writes that "the security situation" "improves within 18-24 months and we can begin going home." But given the way the numbers add up, this seems extremely unlikely. For one thing, they'll have to be replaced by Iraqi soldiers, but if all the American troops are engaged in counterinsurgency, who's training the Iraqis? Current administration policy calls for embedding U.S. advisers within Iraqi units. Kagan is opposed to that policy. He favors expanding U.S. units and having some Iraqi units tag along. He claims that those Iraqis will be trained "much more effectively" his way, "because they will be partnered with and fighting with our excellent soldiers."

This is simply wrongheaded. Indigenous soldiers are best trained by taking the lead in military operations. They gain most legitimacy in a counterinsurgency campaign if the local population sees them as being in charge, not as sitting quietly in the occupier's back seat.

One reassuring moment in President Bush's press conference today came when he said that if he did decide to surge more troops to Iraq, he would do so only if there were "a specific mission that can be accomplished with more troops." Kagan's briefing doesn't spell out that mission, doesn't show it can be accomplished with more troops, at least not with the number of extra troops that are remotely available.