Why do some religions die out, while others persist in the face of brutal persecution? Religious diversity, while not completely analogous to biological diversity, has drastically diminished over the past two millennia; the Big Five resemble dominant and aggressive species, and the various sects and denominations within them, which create the appearance of diversity, are more or less local variations of a single species. Linguistic diversity has suffered a similar fate, worldwide—but even the smallest African dialects are at least still spoken in the home, though the language of commerce and medicine be English or French; while the smallest African cults have vanished utterly, replaced with some form or another of Christianity or Islam.
The first and most obvious explanation has to do with power: Whoever has the most money and the best weapons ends up conquering territory and spreading one particular religion. But this is not the whole story—the Mongols converted to Islam, they didn’t convert the Muslims; and Christianity, though so widespread today, was for two centuries or so a small sect that put its members at a social and political disadvantage. Meanwhile Hinduism stayed under foreign rule for a milennium or more; Judaism suffered persecution from several powers, from the Diaspora to the atrocities of the prior century. So power isn’t the only answer; it may not even be the right answer.
The same goes for mere numbers. There is certainly a feeling of community, and the mutual reinforcement of belief in the company of fellow believers—but the resilience of minorities like Parsees and Jains in India, Jews in Europe, or Mormons in America, should have us seeking for other, or at least additional, explanations.
It seems that some religions are simply more brittle than others: No matter how strong their hold on a given tribe or people, they are quite easy to eradicate or supplant. What makes one religion brittle and another religion hard? The quality is psychological, and so are the explanations.
First, the religion must divorce itself from the material. Judaism, and its monotheistic Near Eastern successor religions, were all three bitterly opposed to idol-making. This refusal to make an image of God kept the God immaterial and hence impossible to smash, deface, or (in the case of, say, God-emperors like Hirohito or Atahualpa) humiliate, imprison, and kill. It was all interior, and hence slippery. You had to kill the people themselves to kill the belief. Hinduism, in this as in so many things containing contradictions, is well known to be the iconopoetic religion par excellence, and the only real surviving one—but it also has an anti-materialistic tendency in the Vedanta, and orally transmitted Sanskrit scriptures, which seem to have provided the necessary slipperiness. No amount of temple-defacing and idol-smashing under sundry Muslim Sultanates could shake India’s bitterly resilent Brahmins; though, of course, numbers were also on their side.
Another crucial psychological aspect is, to put this bluntly, spiritual xenophobia. Hindus, and Brahmins in particular, were notorious for looking down on their own rulers, no matter how wealthy and militarily powerful. The Muslim sultan, like the British Viceroy, were all mleccha, a certain intrinsically crude or dirty foreigner. This contempt, of course, was quite mutual; the Qur’an is brutal on the subject of infidels, just as the Old Testament has little tolerance for rival idols like Mammon or Baal, and those who worship them. The crucial difference between this sense of apartness and superiority, and the more conventional aristocratic disdain of ruling classes everywhere, is that this disdain is not based on physical might, wealth, or grandeur. Even during the Hegira, or flight from Mecca to Medina, the outnumbered and militarily outclassed early Muslims believed they were superior to the Arabian idolaters who drove them out; just as the Jews under Pilate, or the early Christians under Nero, or the Hindus under the Mughals and then the British, each believed themselves to be intrinsically superior to their overlords and persecutors. Religions in which holy awe and worldly impressiveness always go together—like the Incan religion, or any number of now-defunct tribal religions (in other words, religions with a too-close association of state power and spiritual power), end when their power ends. Roman emperor-worship took a long time dying, but it died before the Roman empire did, thanks to the conversion of Constantine.
This aspect suggests why the 20th-century fascist pseudoreligions were the most brittle religions of all: Depose Hirohito, kill the Fuhrer, and the whole enterprise collapses, state and ideology alike. The power, the faith, and the mystery all inhered in a single person. The outcome of victory in World War II—the assimilation of the defeated into global capitalism, within a generation—was, therefore, a misleading exception. Regardless of their military might, Nazi Germany and Imperial Japan were based on brittle religions. Although there were a few “holdouts” on scattered Japanese islands, they were either misinformed or in denial; the population, by and large, gave in shortly after the surrender, and the holdouts eventually gave in as well. This shrug of an old man’s shoulders and laying-down of the kitana is not behavior compatible with the faith, say, of an early Christian. Eisenhower’s main fear, once he crossed into Germany, was that Hitler would move south to an Alpine Redoubt (Alpenfestung), with loyalists engaging in guerilla warfare on mountain terrain: This fear was so real, and so influential on strategy, that he overrode the urging of Patton and Montgomery to advance on a narrow front to Berlin; instead, he opted for a much slower, “broad front” advance. Eisenhower believed that Nazism would live as long as Hitler did; he was probably correct.
Such World War II examples, which so influence American military thinking about the outcomes of war, are examples of brittle religions breaking easily. They do not serve us when we strategize against the imperial expressions of a hard religion like Islam—such as its latest expression, ISIS. ISIS is not a “new” phenomenon; it is simply the latest expression of what is a more or less continuous phenomenon, that of a hard religion refusing to break. Calls for jihad, fatwas against imperialists, military groups whose organizing principle is Islam—these were seen in Egypt during Napoleon’s invasion, and in the Sudan during the struggle against British imperialism; the 19th-century bin-Laden-equivalent was the Sudanese Sheikh Muhammad Ahmad, alias The Mahdi, his followers the nemeses of Gordon and Kitchener and the swarthy bogeymen of Victorian newspapers. The threat of a Pan-Islamist revolt terrified the British Empire during World War I and was stoked by the Kaiser’s Germany (cf. John Buchan’s excellent thriller, Greenmantle). These were all groups utterly outgunned and militarily outclassed, just as ISIS is by the United States. Al-Qaeda is frequently presented in the media as an “enemy” of, or “opposed” to, ISIS—but this is a subtle misreading of the situation, with an associated error of diction. It is, in actuality, a rival of ISIS; it has seen the rise of a more powerful, wealthier, better organized, more ambitious version of itself. Both are Sunni, and the memberships of both are transnational; every Muslim who leaves London to join ISIS is a potential recruit lost to al-Qaeda.
So we know well enough how battles against brittle religions end: With the extinction of the religion. The minds in question are simply reformatted, like a drive. How do battles against hard religions end? We have evidence aplenty about this, too: They don’t. If they do end at all, they end in the triumph of the harder religion—which is why the Americas are majority Christian today, and why the Arabian peninsula turned Islamic in the first place. When two equally hard religions go up against one another, the antagonism never entirely goes away, no matter how asymmetric the warfare—consider “Christendom” and its millennia-long simmering war against Jews, or the long-running antagonism between the West and Islam, which once took the form of Venetians-versus-Turks, and now takes the form of Americans-versus-ISIS.
That latest conflict, too, may well prove a battle between hard religions. Modern Western ideas of democracy act, psychologically, as a hard religion. We have the same focus on intangible or immaterial sacred things (“human rights,” “freedom”), and just as much a sense of intrinsic superiority—that is, we are indifferent to how an autocratic place like Saudi Arabia is dizzyingly wealthy; America is intrinsically better because it is a “free country.” This is part of the intractible nature of 20th-century conflict: In spite of frequently asymmetric firepower and wealth, only the hard religions remain, and in Kashmir, in Gaza, in Iraq and Syria, they fight on, and on, and on.