Immigration. Islam. The west. Christopher Caldwell's book is divided into three neat sections. The structure represents an equation - immigration multiplied by Islam equals the collapse of the west. The logic behind it is simple: in a fit of absent-mindedness, western Europe has opened its doors to an "adversary culture" based on the "hyper-identity" of Islam. The Muslim immigrants came to Europe intending to "seize territory" and they are now ready to "colonise" Europe. Civilisation as we know it will disappear once Europe is integrated into the House of Islam.

This is not an original thesis. It has all the hallmarks of a post-Enlightenment orientalism that saw uncouth Muslim hordes as a danger to Europe. But Caldwell, an editor at the American neocon magazine the Weekly Standard, adds a couple of novel twists. Old-fashioned orientalism was all about keeping Muslims at bay. Caldwell is more concerned with protecting the "essence of Europe" from contamination by "non-natives", whose very presence threatens our freedoms and imperils our lifestyles.

While retaining the basic features of orientalism - the framing of Islamic values as the antithesis of Europe, the equation of Islam with fanaticism, violence and despotism, an obsession with Muslim women and the veil - Caldwell has had to accommodate to changing circumstances. The issue today is no longer maintaining the supremacy of the west. In Caldwell's neoconservative reformulation, orientalism becomes an instrument for shoring up the declining influence and hegemony of the United States. The real anger of Reflections on the Revolution in Europe is directed not towards Islam and Muslims, but towards a Europe that has "emancipated" itself from, and hence abandoned, America. Caldwell uses orientalist tropes to strike fear in the citizens of Europe, urging them to wake up to the enemy now in their midst. Europe's duty is not to its former colonies, or else to some utopian ideal of a fair and just world. Rather, it is to embrace America, its manifest destiny.

That we are firmly in neo-orientalist territory is clear from the start. Caldwell reminds us of Samuel Huntington's warnings about the coming clash of civilisations and Islam's "bloody borders". Huntington's observations about "the frictions between Islam and every single culture with which it is in contact", he argues, are even more pertinent in a globalised world. Islam is distinguished by the "penury, servitude, violence and mediocrity of Muslim societies worldwide". And just in case we have reser­vations about Huntington's "observations", Caldwell conjures up more dead, white orientalists to prove his point. The venom poured out against Islam and Muslims by the aggressively anti-Semitic Ernest Renan and Hilaire Belloc is quoted with gushing approval. Given that so many European and American authors have reached the same conclusion, we are told, Islam must be intrinsically malevolent.

What this means is that the diversity of Islam is an illusion that masks a deeper truth - namely, that problems of immigration are in fact aspects of a larger, overarching clash of civilisations. Moreover, there is no point in relying on "moderate" Muslims in this conflict, as there is no such thing - moderate Muslims, such as the reformist scholar Tariq Ramadan, are in fact secret fascists. Indeed, Caldwell suggests that Ramadan's ideas are identical with those of the murdered Dutch politician Pim Fortuyn: they both present Islam as a religion of domination that is about to overwhelm and subdue Europe.

Caldwell warns Europeans not to think that Muslims are a minority. There may be only 15 million Muslims in Europe - constituting less than 4 per cent of the EU's total population of 493 million - but they breed like proverbial rabbits. In Austria, he asserts, their fertility rate is twice that of the "natives". They will overtake the "native" population in less than 50 years, whereupon they will declare Austria an Islamic republic. Muslims have already taken over several major European cities: Amsterdam, Marseilles, Berlin, London and Manchester, to name a few. There may be fewer Muslims in some European countries than the Bolsheviks in Russia in 1917, but they are just as potent and eager to conquer.

Indeed, according to Caldwell, the Muslims are Bolsheviks in disguise. And Islam, like communism, is a "total social phenomenon", in that it is "capacious enough to accommodate a wide variety of grievances" and "appeals to people of all different backgrounds and social classes". Stalin was a "modern commander of the faithful". Since the fall of the Berlin Wall, Islam has taken the place of communism; it now presents a similar mortal threat to Europe.

It is impossible to take such nonsense seriously. For one thing, there is a strong streak of paranoia in the analysis, and Caldwell is unable to differentiate between "integration" and "assimilation". He regards "primitive" Muslims, even those born and bred here, as "non-natives", but Jews as indigenous - even though they were being described in exactly the same manner as Muslims less than three generations ago. It is acceptable to be called anti-Semitic if you criticise Israel, but not to be labelled an Islamophobe if you are anti-Islamic and prejudiced towards Muslims. Caldwell says that in Europe, the 11 September 2001 attacks were met with indifference - and in the process neatly glosses over the small matter of Europe's role in the invasions of Afghanistan and Iraq.

His manipulation of statistics is crude, too. Birth rates among European Muslims are falling, not increasing. In Austria, recent research has shown Muslim birth rates to be far below those of people without religion, and below even those of Protestants. If we consider Austrian "natives" to be exclusively Catholic, then the "native" population of Austria will indeed be overtaken by 2051, yet exceeded not just by Muslims, but by the rest of the population, too, including Protestants and the biggest majority of all - people without religion. Caldwell fails to consider the consistent upward mobility of Muslim women throughout Europe, as well as countless examples of successful integration. And he simply ignores the many surveys that show Muslims to be exceptionally loyal to their respective European countries.

Ultimately, Caldwell wants Europe to be less tolerant. Instead of officially recognising minorities, which is "dangerous", we should follow the United States, where "immigration is Americanisation". It is a myth, the author contends, that America is an open society. Rather, it "exerts Procrustean pressure on its immigrants to conform" - America is about homogeneity, not diversity.

Reflections on the Revolution in Europe is a rudimentary amalgam of every orientalist prejudice known to man and history. As the carpet is pulled from beneath the American hegemon, Caldwell looks towards Europe for support in a last act of defiance. The book is symptomatic of a reactionary culture gone pathological, and offers good evidence, if indeed evidence were needed, of the vacuity and viciousness of neoconservative thought.

Ziauddin Sardar's most recent book is “Balti Britain: a Provocative Journey Through Asian Britain" (Granta, £9.99)

Reflections on the Revolution in Europe: Immigration, Islam and the West
Christopher Caldwell
Allen Lane, 376pp, £14.99