Ayaan Hirsi Ali wants the rest of the developed world to adopt Australia’s immigration and refugee policy.

She doesn’t say this explicitly. She doesn’t even seem to have investigated the land Down Under in any detail (although she’s a dab hand at quoting telling observations from Australian prime ministers). But in Prey: Immigration, Islam, and the Erosion of Women’s Rights, Hirsi Ali unintentionally recapitulates arguments made by Australian politicians of both left and right over the last thirty years. These turned on how to make immigration pay, on how to make it popular, on how to forge a national identity based on it, and how to stop it colonising every other issue that comes up for debate in a liberal democracy at election time.

It’s probably best to state what Prey is not before going further: a great deal of nonsense has been written about it, including in once reputable outlets (looking at you, New York Times).

Critics have taken not only to reviewing the author, but also to reviewing the book they wanted Hirsi Ali to write, reviewing a strawman of her book, or reviewing a different book altogether—one Hirsi Ali would doubtless struggle to recognise. At no point in Prey does she evince opposition to immigration qua immigration. What she opposes is as follows: open borders; the claim that developed countries owe (as a matter of duty rather than a voluntary expression of compassion) people fleeing developing countries access to their wealth, and the related argument that immigrants are at bottom interchangeable widgets. For this Australian-born reviewer, every argument she makes is smack-dab in the middle of the country’s political mainstream.

What has made the book explosive for non-Australians is the way Hirsi Ali prosecutes the “immigrants are not interchangeable widgets” point. In standard economic analyses, civil servants and policy wonks look at labour-market participation and workforce productivity rates among immigrant populations, controlling for things like education, language proficiency, time in the new country, national origin, and refugee status. Hirsi Ali, by contrast, builds her case around differential crime rates based on religion. In a series of forensically detailed chapters, she deploys a wealth of data and presents it to the reader with considerable scruple. 

Her argument in a nutshell is this: although almost 3 million people have arrived illegally in Europe since 2009, close to 2 million in 2015 alone, this is the least interesting thing about them. What matters is that two-thirds are male, 80 percent are under the age of 35, and that where maleness, youth, and Islamic religion coincide, rates of sexual offending go through the roof.

Her next claim—following on smoothly from the first—is that this bad behaviour bears particularly hard on women, but not all women equally. The primary victims are working-class women. In areas where most people are white, poor white girls will be victimised. In areas where populations are mixed, then poor girls of any race will be targeted (in Britain by the numbers, the criminological rank-order seems to be poor whites, poor Sikhs, and then poor Jamaicans). There’s also evidence similar crimes were initially perpetrated against poor girls within relevant Muslim immigrant populations, although this is harder to prove.

At this point in Prey, organised feminism comes in for a richly deserved pasting.

Lobbyist-feminism has been captured by squeamish ideologues who—in the name of intersectionality and decolonisation—routinely embolden and empower those promulgating contempt for the Enlightenment values on which feminism’s historic achievements depend. When Britain’s Grooming Gangs scandal broke, for example, feminism à la mode was conspicuous by its absence. Only unfashionable radical feminist Julie Bindel swam against the tide and insisted on honest reporting, and she was often pilloried for it.

In 2015, the UK’s Fawcett Society commissioned a large opinion survey from leading pollster Survation. Among other things, it revealed only nine percent of British women considered themselves “feminist.” At the time, this low figure was explained away by reference to problems of representation. Half of British women consider mother, wife, or partner to be their most important identity, for example, not their job or other public-facing role. An increasingly corporate feminism—one worried about boards and banks—seemed to be something to which many women could not relate.

However, Hirsi Ali sets out a compelling case that organised feminism absenting itself from public comment about Grooming Gangs and child sex offences meant it finished up in seriously bad odour among working-class women who in different circumstances would likely be sympathetic. If she’s right, then posh girl feminism is in the process of squandering one of modernity’s crowning glories—woman’s freedom to live by no man’s leave.

Peak violent criminality occurs in males between the ages of 15 and 35. If Europe had admitted three million Japanese in that age range, 80 percent of them male, violent crime would have gone up. It is impossible to hide eight to nine times greater male over female violent crime rates. All you need do is look at the relative sizes of the two wings of the UK’s prison estate. However, violent male criminality in that age range among Muslim immigrants—and especially refugees—is higher than it is not only among the native male population, but also immigrants and refugees from every other ethnic and religious group.

Hirsi Ali argues that—apart from Islam—the most salient additional criminogenic factor is widespread, state-and-religiously-sanctioned polygamy in the immigrant or refugee’s home country. This fact is so significant that it’s sometimes possible to disaggregate data and compare the crime rates of Muslims who come from countries (or sects of Islam) that condone polygamy with those that don’t. The exercise is instructive and does not flatter the former.

Polygamy pre-dates Islam (Hirsi Ali observes, drily, that one needs the most casual acquaintance with the Bible or Hindu epics to know this). However, history going back some two-and-a-half thousand years means the two great missionary monotheisms have diverged profoundly from each other when it comes to the status of women, and this parting of the ways started with different marriage customs.

Very simply, Europe was conquered by the Romans, and the (pagan) Romans were monogamous. The colonial power then imposed its civilisational family values on subject peoples in a manner to make the governors of British India blush. Relatedly—and under severe Roman pressure—Judaism also became monogamous. Christianity, which grew up under the Romans, adopted their monogamy. Christianity also endorsed the Roman horror of consanguinity, banning cousin marriage everywhere it took root.

Because the human population sex ratio hovers around 50/50, when one man takes an extra wife, another man is deprived of the opportunity to marry at all. Even if only one man in ten has a single extra wife—a modest degree of polygamy—that means fully 10 percent of men are shut out of the marriage market. This sets off a mad and violent scramble among young men not to end up in that unfortunate “bottom 10.” Otherwise, the options for obtaining sex (at least with a woman) are reduced to two: subterfuge or rape. When I studied Civil Law (necessary to practise in Scotland), I remember asking my Roman law tutor why that civilisation’s lawyers had such a set against polygamy. He said, flatly, “it makes people violent; if you want to pacify a large area, abolishing it is absolutely the right thing to do.”

Hirsi Ali then proceeds to set out the evolutionary evidence as to the consequences of polygamy. It is all rather grim, but evolution is a numbers game. Religious intentions or happiness are beside the point, which means the higher the degree of polygamy in a society, the stronger are its negative effects.

Those include turning women into rare commodities which, because of artificially created scarcity, are subject to stringent controls in all aspects of life; decreased age of wives relative to husbands on marriage, sometimes to the point of paedophilia; more children per woman, with less reproductive choice; much higher rates of domestic violence and child abuse; higher crime rates, especially rape and murder; and, finally, more frequent warfare. To their credit, the Roman jurists (without the benefit of modern population genetics and its intimidating mathematics) noticed about half of these. Maybe there is something to being the first civilisation to carry out census-taking in its modern form.

This, Hirsi Ali argues, is the true source of the rift between Islam and the West, but also between Islam and modern Confucian civilisation (China, Japan, Vietnam). Islam never gave up polygamy. Instead, it enshrined the practice in Sharia, allowing men up to four wives, and captive concubines into the bargain. In doing so, it ensured women could not rise in social status—a rise that seems natural and inevitable to us—and condemned itself to suffer ongoing instability generated by large numbers of unattached young males.

Hirsi Ali does not want to “shut the gate” on Muslim immigration, although she’s a big enough person to admit data she assembles could be used to advance such a policy. Her desire to provide a route out of the religion and the countries it dominates (particularly for homosexuals and apostates; both are routinely executed) means she lifts Australia’s approach entire.

Abrogate the 1951 Refugee Convention. Impose mandatory detention on illegal arrivals. Turn back the boats. Deconstruct community networks. Bang up Muslim sex offenders. Make citizenship hard to get and demand integration as the price of admission. Remove all forms of “cultural mitigation” while imposing heavy sentences: in one celebrated Australian case, Muslim gang-rapists had their sentences aggravated rather than mitigated when counsel tried to argue that they couldn’t cope with the sight of women in bikinis and short skirts.

Related to this is a willingness to deport not only terrorists but also their enablers. Deconstructing the community networks protecting and nurturing the views that give rise to terrorism is one of the better options we have available to us. When you have poison in a wound, you draw it. When you have people determined to provoke conflict between groups, you expel them. Deportations are a legitimate and necessary tool for dealing with networks of extremists. Peter Dutton, Australia’s one-time immigration minister, boasted of how many criminals he’d deported, something Australia has done for years, occasionally with such intensity individuals have been rendered stateless.

Likewise, it has tailored its immigration policies such that incomers of whatever stripe are overwhelmingly middle-class and educated. In this context, be aware that the majority of Australia’s Islamist “foreign fighters” (the total number is small) are from a single region in a single country (Lebanon) and from families admitted to Australia before its points-based immigration regime was instituted.

The Australian system has a pleasant side effect in addition to avoiding the Muslim integration failures that have beset Europe and the US in recent decades. It makes immigration irrelevant as an election issue. The two political parties with extreme policies—open borders Greens and “shut the gate” One Nation—struggle to win ten percent of the vote. Labor (centre-left) and Coalition (centre-right) present a complete unity ticket.

It does, however, mean giving up one part of universal liberalism: Australia accepts that there are average differences between groups and develops policy on that basis. Its system is designed to attract law-abiding workers, not generic people, so it values workers more. This can be a shock to liberal universalists, with the more numerate among them pointing out that while criminal propensity for a given group may be X, we should assess individuals as they come. Given what Hirsi Ali documents, it’s possible this fine heuristic can be applied successfully only to citizens and permanent residents. Immigration, like all public policy, is playing the odds game.

When I was small, my father always enjoined me, “try to think your thoughts through to the end.” Prey is evidence that many countries—particularly in Europe—have not done so when it comes to immigration and refugee policy. Hirsi Ali says that needs to change.