NAOMI KLEIN is a polemicist. If you agree with her you may find her compelling. If you disagree, it is easy to dismiss her work as hogwash.

No Logo, published in 1999, gave Klein chief cheerleader status with the anti-globalisation brigade. Her alarmingly titled new book revisits the “all-capitalists-are-pigs” credo. But this time her illustrations are altogether more chilling.

No Logo demonised multinational corporations such as Nike and Wal-Mart for selling hollow brand ideals to gullible consumers while exploiting Third World sweatshops. The Shock Doctrine attempts to show that free market economists harness catastrophes to impose brutal reform on subjugated populations. Untold riches, Klein claims, are gathered by a corrupt few while oppressed majorities pay an enormous price in shattered livelihoods or violent abuse.

Natural disasters, including the Asian tsunami and Hurricane Katrina, she says, weakened societies so that they were unable to resist free market zealotry. Man-made shocks have performed a similarly obnoxious role — she cites September 11, Tiananmen Square and post-apartheid South Africa.

Mercifully, she refrains from suggesting that disasters were purposefully manufactured by an axis of evil economists, although she comes close on occasion. Fans of conspiracy theory will delight as she casts aspersions left, right (especially) and centre. But even the most credulous must question parallels between the sadistic electro-shock experiments forced on Canadian psychiatric patients in the 1950s and attempts to rebuild eastern bloc societies after the implosion of Soviet-style command economies. It is a powerful metaphor, but it goes well beyond the bounds of reason.

Klein is not afraid of generalisation. She writes: “It is not an exaggeration to say that the War on Terror industry saved Israel's faltering economy, much as the disaster capitalism complex helped rescue the global stock markets.” This, and similar sweeping statements are grotesque exaggerations.

The Shock Doctrine is lucidly written and comprehensively researched, but leans heavily on partisan contributions from the cuttings library and the blogosphere. Ultimately it fails because it is too easy to dismiss as a leftist rant. Klein derides the “disaster capitalism complex” and the profits and privatisations that go with it but she does not supply a cogently argued critique of free market principles, and without this The Shock Doctrine descends into a muddle of stories that are often worrying, sometimes interesting, and occasionally bizarre.

The free market is not flawless. Economic reform can create unnecessarily harsh realities and is not always successful. Klein's achievement would have been greater if she had placed these shortcoming in the context of an acceptance that free markets usually improve living standards, promote peaceful co-existence and develop civilised societies.

The Shock Doctrine: The Rise of Disaster Capitalism by Naomi Klein

Allen Lane, £25; 576pp

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