It is surpassingly strange when someone reductionistically posts a supposed single explanation of a widely divergent phenomenon such as war, and yet has the temerity and unmitigated gall to tell others that do not hold to their explanatory meme (not even a memeplex, for this requires multiple memes) that THEY are the float-on-the-shallow-foam simplistic ones.  If such a population-pressure-exigency-to-make-war mechanism kicks in, it is not memetic, but genetic.  Thus it can be either exacerbated or dampened, or perhaps even overridden, by other, more memtic factors, such as ideology.  It is in the spirit of proferring an example that is grasping towards this deeper, more complex, subtle  and nuanced understanding, which unlike yours, is not so oversimplified that it fails the Occam's Razor corollary of explaining all the relevant phenomena, that I post the following essay.

The war of ultimates
Religious war is back in full force
by Donald Sensing
http://www.donaldsensing.com/2004/06/war-of-ultimates.html

There have been several, though not a lot, of causes of war in history. Some theorists have said that all wars' causes really devolve down to the one and same cause, "population pressure" in the words of Robert Heinlein or "resource intensification and depletion" in the work of anthropologist Marvin Harris, which is another way of saying the same thing.

But these theories do not account for the influence of religion or ideology in militarizing a society to the point that it launches aggressive war upon its neighbors. For example even if we allow that population pressure reached critical mass for the ancient, pre-empire Romans, it does not explain why they decided to manage the crisis through military expansion rather than increased trade or other peaceful arrangements.

Populations, not just individuals, are prone to delusions of grandeur. Whatever made the Romans set off toward empire, the time came when empire was its own justification. Conquest "for the glory of Rome" was reason enough. Ideologies are always self-justifying. For all its achievements in engineering and law, the Roman empire was cruel and harshly oppressive.

Germany had been bled white by the Great War (as had France and England), and had suffered enormous deaths from the postwar influenza epidemic that took more lives than the war, worldwide. But those human losses didn't stop Hitlerism from taking root and growing into the nihilistic monstrosity that shook the world.

Religion is not immune, of course, to the dangers of sliding into ideological absolutism. Before the end of the Roman empire, the Church had become a heavy political player in its own right, culminating the right of the Pope to crown Charlemagne as emperor, a right that continued until Napoleon snatched the crown from the Pope's hands and placed it on his head himself.

With the crowns of Europe and the seat of Peter in a mutually back-scratching relationship (most of the time), a strange religious-political symbiosis developed that finally enabled Pope Urban to command them to conquer the Holy Land from Muslim rule in the name of Christ. That Europe had been fighting the Islamic empire for a few hundred years, in varying intensity, made the command much easier to obey. But it did turn a rather conventional series of wars about territory into a Holy War all around.

Territorial disputes can be permanently resolved. "54-40 or fight!" never became a war cry because Britain considered the land concerned - a border dispute in the American northwest - was not worth fighting for. Now the matter has been relegated to history, never to rise again.

But religious and ideological conflicts (RICs) exist not on the earth, but in the mind. What is at stake is not fishing rights or trade routes or minerals or arable land, but the warring parties' fundamental understanding of reality and their place in it. Although mundane concerns are never entirely absent from RICs, they really form the opportunity for conflict rather than the underlying cause. The cause is absolutism that allows for no competitors.

I think the American Civil War fits into that category. It's a little too facile to say that had the North and South known in early 1861 that warring over their respective, irreconcilable ideologies would take hundreds of thousands of lives, that they would have found another way to resolve them. I'm not so sure they would have or could have. As Lincoln said, the country could not continue to exist half slave and half free. No compromise was possible any longer. They had all been tried.

The war on terror is a war of ultimates, too, although I don't think that many people of the West realize it. Our al Qaeda enemies certainly do. Al Qaeda, however, is more extreme than post-Roman Western history is generally familiar with (Nazism being a notable exception) because Islam is the most complete merger of politics and religion the world has seen since its inception, certainly more complete than, say, bushido Japan.

An historical, basic tenet of Islam, not just radicalized Islam, is that all human affairs of any kind must be under divine control, mediated through sharia. The present, clear separation of religion and politics that the West took centuries to develop is formally absent from Islam, the radical variety or not. Fortunately, most Islamic societies have honored this total integration only in the breach. But al Qaeda et. al. say that the return of Islamic societies to the rule of strict sharia law is a non-negotiable goal. (It can be argued, I think, that no such "return" is possible for the simple reason it never really existed as al Qaeda thinks. Islamic societies are really post-Muhammed, and they immediately began adjusting the tenets to cultural and political realities, all the while claiming they were the True Faithful.)

Islam, not just the radicalized version, teaches that Allah's control over events of the world and human life is total and complete. Pretty much the extent of human free will is either to rebel against Allah or to submit. Yet even rebellion is, somehow, under the controlling purview of Allah. Everything that happens, without exception, is the preordained will of Allah.

Osama bin Laden bombed two American embassies in Africa killing mostly Muslim Africans by the hundreds. The Quran prohibits murder, and especially forbids Muslims from killing other Muslims. An ABC reporter subsequently managed to interview bin Laden and asked him whether he was responsible for the deaths of the other Muslims. No, replied OBL, I am a tool of Allah, and whatever I do is determined to happen by Allah. Those people would have died at that time in any event, because it was Allah's will that they die.

In Islam, Allah holds all the power marbles. Humanity has no true self will or self power.

Bin Laden's sort of self-justifying extremism is not the mainstream of Islam, but neither is it as far removed as we might imagine. Fatalism is a characteristic of Islam. There is no human freedom. Human liberty, especially as Americans think of it, is literally a foreign concept to Islam, especially Arab Islam.

We say that the defining idea of American liberty is "self evident:" Human beings "are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness." This claim has no natural fit with Islam. The idea that humans, created by the power of Allah, could inherently possess unalienable rights of their own, which no authority may remove, would require Islam to surrender the idea that Allah enjoys meticulous control over all affairs of nature and humankind. But this notion is lethally dangerous to the defining idea of Islam itself: that Allah has all the power.

Liberty as we conceive it is at the heart of the conflict. For Muslims, the most desirable state of human society is not one that is free, in the Western sense, but one that is submissive to Allah, according to the dictates of Quran. This state of society is dar al Islam, the world of peace. Anything else is the dar al harb, the "world of war." Societies, peoples or nations are either at war with Allah or at peace (through submission) to Allah.

This concept of submission is the matter of ultimate concern to Islam generally and is enormously amplified by radicalized Islamists such as Osama bin Laden and his allies. Hand in hand with this ultimate concern are what we would think of as territorial, political, legal and social concerns, namely the ejection of non-Muslims from Saudi Arabia and other Persian Gulf countries, the imposition of strict rule of all-encompassing sharia over every facet of human affairs, and, longer term, the restoration of the lands of the old Caliphate to Muslim dominion.

In their view, no sacrifice is too great to achieve those ends, and no violence is unjustified.

I don't think we have reached the point yet of widespread American understanding that the war is one of ultimates for us as well.

Dennis Mullin, who traveled widely in the Islamic world for 10 years as a foreign correspondent for U.S. News and World Report and other publications, wrote in the WaPo last year that "The present war is really a crusade" fought by Islam against the West- and non-Western non-Muslims.

The al Qaeda leader, in the "Letter to the American People" published last November and attributed to him, [made] very clear that bin Laden's ultimate goal is to undermine Western civilization in its totality, which strongly implies that even if Israel didn't exist, he would still be pursuing what is really, as reluctant as we are to say it, a religious crusade in the true historical sense.

Throughout history, disruption of the social and political order of the day has been a regular occurrence. But this is a different kind of fight, one with long roots in the past and one that will last long into the future. In the letter, bin Laden purportedly said, "it is to this religion that we call you," implying the need for a global theological upheaval. ...

Lest there be any doubt that what is going on now is a real crusade, and not just a protest against American hegemony, it is important to note that al Qaeda and other Muslim forces are now or have been engaged in conflicts not just against the West proper, but against Hindus in Kashmir and increasingly in other parts of India, as well as against Orthodox Russians in Chechnya. Moreover, the Muslim Uighurs are fighting the mostly Buddhist Chinese; and Muslims are doing battle in Indonesia and the Philippines. Hundreds were recently killed in Muslim-Christian violence in Nigeria over a beauty pageant (ironically won by a Turk, after it was moved to London). Muslim extremist cells are operating in scores of countries, and their cross-border cooperation in training and financing gives credence to the assumption that the driving force is not strictly localized grievances (witness Kenya, Bali) as much as a clarion call to a worldwide transnational Islamic revival. ...

Absent a true reformation within Islam itself (which seems increasingly unlikely), the frustration over the present and the dreams of past glory of the 7th century are manifested by a destructive effort to bring the rest of the world down to Islam's current level.
Our enemies wish us lethal harm, have present means to inflict it and are developing means to deliver mass destruction to our shores. There is a large, well-funded terrorist organization, active in many nations, possessed of men who will die to achieve their aims, which has already claimed the right to kill four million Americans. Sept. 11, 2001 proved that they have the will to do so. If Iran's mullahs or North Korea are not actual allies already, they will be, especially if we give them or their successors years and years to do so. The campaign against terrorism is foundationally a contest of wills - and dare I say it, a spiritual struggle.

The real issue is whether the Western Civilization shall prevail against the last vestige of medievalism; whether the rule of men who behead their prisoners, enslave their women and deny the rights of self-determination to their own people, shall kill us and displace us, to whom the individual and individual rights are sacred and whose laws require respect for freedom of conscience, freedom of religion and whose traditions preserve freedom from fear and cruelty. In the long history of civilization, this task is to be done now.