This is one of the main problems with Nick Cohen, a columnist on The Observer and for a time the Evening Standard in London, who also chips in comment pieces for the New Statesman, a weekly magazine of the liberal-Left. Cohen has some points to make but manages to mangle the job by constant sneering and by substituting rhetoric and anecdote for research. He doesn't seem to realise that the tricks of the trade that work when you are writing a punchy diatribe in a newspaper just look tawdry when you spin them out over 405 pages.

The core of his argument is about the crisis on the Left, crystallised by the collapse of the Soviet Union in 1991. He points out that some activists are good at protesting (about globalisation, anti-capitalism, environmental degradation and so on) but appear have no alternative programme. He characterises this as a form of unacceptable pick-and-mix 'consumer anarchism'. He identifies 'identity politics' as another form of retreat and dismisses Leninist vanguardism and Marxism as lost causes.

Well, you may agree with some, or all, of this but it has certainly been on the radar for some time. If he had been doing a proper job of identifying the post-1991 political architecture he would also have singled out Blairism, or 'Thatcherism lite', as an attempt to stay in step with globalisation. (But, as someone who made his name attacking the market-led trajectory of this brand of 'social democracy' in the late 1990s, that would be tricky. He would have to confront his own politics, which are clearly in transition.)

The war in Iraq is a central theme of the book: for Cohen the Left was wrong to oppose the invasion of Iraq and its 'failure' was symptomatic of a more deep-set sickness. The kernel of his position is that Iraq was a fascist regime and that democrats ought to have felt honour-bound to oust it. The reason that they didn’t was because they were so obsessed with the alleged inadequacies of liberal democracy that they could not rise to the challenge of real injustice. This explains why he supported the war, and supports the occupation, and why he enrolled with the neo-conservatives in America, including Paul Wolfowitz, signatory to the document Project for the New American Century, former deputy defence secretary under George W. Bush, and former head of the World Bank.

The cornerstone of Cohen's position is in an extract from an interview with Kanaan Makiya, the Iraqi author who wrote The Republic of Fear, which exposed for the first time the Saddam regime. Makiya, a former Trotskyist, who broke with Marxism over Iraq, says he backed the neo-conservatives because he believed that the State Department’s policy of containing the regime through alliances with feudal kingdoms like Saudi Arabia was wrong. As Makiya says: "The United States should reach out to peoples not governments, to focus on democratisation as opposed to stability. That school of thought emerged in the Pentagon, led by people like Paul Wolfowitz."

For many on the Left throwing your support behind the Pentagon in this way is akin to going into partnership with the Mafia; irrespective of the warm words they utter at the outset to buy support only an innocent would take it at face value. The crucial word in Makiya’s comment is 'democratisation', six syllables with radically different meanings. For the Pentagon, liberal democracy can mean kicking out dictators (unless, of course, they are in Pakistan, Uzbekistan or some other geopolitically important place) but it has little to say about social justice and giving trade unionists a vote on how they run their lives.

Democracy, the free market and inequality go together like a horse and carriage, hence the mass privatisation of state assets in Iraq along with a cold-shouldering of the embryonic labour movement. For the socialists around the New Left Review who supported Makiya as he wrote his seminal account of the Saddam regime in the 1980s 'rule by the people' also includes political freedom but it goes a long way beyond the traditional once-every-five-years recipe as Hugo Chavez, for instance, is starting to demonstrate in Venezuela, much to the annoyance of the US. For a desperate expatriate like Makiya needs must. But whereas Makiya probably knew what he was giving up by cashing in his chips in this way Cohen doesn’t seem to get it at all.

However, irrespective of whether you agree with the arguments he puts forward, does the book add to the sum of human knowledge? Does it provide insights that pull you up sharp? Does it include arguments, which, however, irritating, lead you to pause for breath and re-evaluate long-held attitudes? The answer to these questions is no.

Anecdotal evidence supplied by journalistic friends substitutes for statistical backing on crucial questions, for instance, over the nature of the conflict in the Balkans. If you dare to contend that the conflict could have been a civil war, rather than a one-sided ‘genocide’ you just come in for abuse. "The job of endorsing the Major government’s appeasement fell to a motley collection of splenetic Trots, ageing Stalinists, elder Quakers, anti-capitalists who forgot about the global justice in Bosnia’s case, and Greens more interested in saving the whale than saving the Bosnians. Bringing up the rear was Harold Pinter, the future Nobel Laureate." This is teetering on self-parody: what is a 'motley collection'? Is that bad? Are we disenfranchising Quakers and Stalinists over 55? What is he talking about. I also wonder which group the late Tom Walker, a Balkans expert that The Times employed during the 1990s, fell into. He certainly took the view that is was a savage civil war.

The book is annoying, but that is almost solely because it is so sloppily written, rather than because it raises awkward issues. One example will give a taste. Talking about the Kurds he writes; "To make matters worse, you could not really blame 'capitalism' or 'Western imperialism' for their suffering unless you went back to the failure of the great powers to establish a Kurdish state at the end of the first world war." The word 'really' gives it away really; it means yes you can. The 'Middle East' was manufactured by the 'great powers' in the Sykes-Picot Agreement in 1916. The Kurdish area of Iraq was included because of the oil around Kirkuk. Just look at the straight lines drawn with a ruler by Major-General Sir Percy Zachariah Cox, the British representative in Iraq, when he carved up the region at the behest of Lloyd George. That is why authors like David Fromkin wrote books with titles like A Peace to End Peace: Creating the Modern Middle East 1914-1922. The Kurds were promised a separate state at the Treaty of Sèvres in 1920, a pledge that was quickly abandoned, while the 1922 British mandate for Palestine wrote the Balfour Declaration into the text, legitimising Zionist colonisation.

Cohen is obviously piqued that pundits of his calibre have been pushed aside by the hoi polloi opposed to the war. How could so many have got it so wrong? He cites a number of barely credible reasons for this, chief of which is that liberals are in thrall to a gang of second-rate thinkers. Of the intellectuals and writers who fall under the axe the late Edward Said, it is claimed, refused to condemn Saddam Hussein because he was a useful asset in Said's campaign for Palestinian rights. Chomsky fails the test because his 'conspiracy theories' theories about the press don't hold water. Some of the stuff borders on the dotty: Virginia Woolf gets it in the neck for being a snob and HG Wells, who was doing the rounds well before the Treaty of Sèvres, gets the thumbs down because he supported eugenics, which was popular 100 years ago. He is also quite content to insinuate that anyone who uses the word 'Zionist' adjectivally to characterise Israeli colonial settler policies is not a thousand miles removed from being a fully-paid-up anti-Semite.

But at one point in his tirade against the Tories over the Balkans (Milosovic was another fascist that the West was right to eliminate) Cohen does give us a clue as to how a leftish-wing social democrat can suddenly disappear into the undergrowth and come out as a neo-conservative fellow traveller. He picks up on the argument between Tom Paine (cuddly Tom rather than ugly old Robespierre) in his battle with Edmund Burke, siding with Paine’s support of universal rights and rejecting Burke's scepticism. The Tories are still glued to Burkian politics 200 years later but Cohen is prepared to back democracy anywhere in the world just as Paine was. As he says: "The idea that liberalism imposed the obligation to support those who supported liberal values was as beyond most liberals as it was beyond most of those who called themselves socialists."

So we get the picture: Cohen is a time-machine Jacobin à la revolutionary France in 1792 along with Citizen Wolfowitz, Citizen Perle, Citizen Rumsfeld and Co. standing up for the principles of liberal democracy (pluralism, regular elections, the rights of the individual, the rule of law separation of powers). There is no empire to guard, no oil, no Saudi Arabia, no tinpot feudal fiefdoms in the Gulf, no elected government of Palestine to hammer into the ground. It's just me and Maximilien 'the incorruptible' Wolfowitz. Something is going badly wrong here.

Diana Raby, who covers some of the same ground as Cohen in Democracy and Revolution: Latin America and Socialism spells out what in a discussion of the gulf between the hollowed out neo-liberal version of 'liberal democracy' that is now orthodoxy and what democracy, meaning substantive rule by the people over their lives, ought to mean. As she says: "As it became clear that social democracy, never revolutionary but at least the guardian of basic welfare rights and public services, had sold out to the neo-liberal doctrine of market efficiency and individualism the political system began to suffer a crisis of credibility not seen for generations, arguably not since the 1930s. The system is still far from collapse but as the abandonment by social democracy of any pretence of commitment to socialism or working- class interests becomes clearer popular cynicism about politics and politicians reaches new heights and electoral abstentionism grows apace."

Cohen seems to believe that thinking of himself as a Jacobin puts him in the vanguard when in fact it puts him in the rearguard, along with the oligarchs. It means that he has accepted a definition of demos that was progressive 200 years ago (in comparison with aristocratic and monarchical tyranny) but is now almost in crisis mode in a world dominated by the imperatives of global economics that talk at length about the rights of private property but have little or nothing to say about social justice. That is why the liberals 'went berserk' over Iraq as he puts it. The charade had become humiliating. They had had enough. That is why there is so much, often uncritical, support for Chavez. At long last a liberal democracy is producing the goods instead of telling lies and managing down expectations.

Even born-again Jacobin Cohen is uneasy about the free-market politics of his new mates in the Pentagon though he cannot quite bring himself to confront it. After all he made his name lambasting the Blairites for peccadillos like the Private Finance Initiative and undermining the National Health Service and now he has got in bed with confrères who are privatising everything in sight in Iraq in an unbelievable fire sale and think that Structural Adjustment Programmes are a panacea for 'failed' and 'rogue' states. (He ought to read The Bush Agenda by Antonia Juhasz, a book based on genuine research that uncovers the links between the American political establishment and firms such as Halliburton and Bechtel in amazing detail.) It is now clear that despite the curbs in the new Iraqi constitution (clause 111) on foreign exploitation of gas and oil resources they are also well on the way to becoming a dead letter. At the same time that Latin American countries are taking back control of their energy resources the Iraqis are being bullied by economic pressures into handing over theirs.

With some books it is possible to learn a lot even if you disagree with the conclusions the author, for instance Makiya, reaches. This, unfortunately, is rarely the case here. The Labour party did not adopt an anti-appeasement policy in 1935 because, as Cohen claims, it felt honour-bound to fight fascism but because Ernest Bevin knew a second war with a major industrial nation was just around the corner. If Germany had been the size and strength of Rumania (or Iraq) delegates would have passed a pious resolution and moved to the next business. Most progressive-minded people in the West do object to fascism just as much as Cohen but they take the view that sovereign states should where possible be left in peace. At no point in the book is there any discussion of the concept of imperialism. There is a big difference between volunteering to go to Spain to fight fascism in 1936 and sending in the Sixth Fleet and General Schwarzkopf to bring the natives to their senses in 2003. If Cohen thinks that the Saddam regime was fascist and had to go we are only counting the days before Iran feels the taste of another slice of 'shock and awe'.

Reading What's Left? I was regularly reminded of comments made by Vincent McGrath and Micheàl Ó Seighin, two of the five Irish men who were jailed for contempt for 94 days in 2005 after they breached an injunction obtained by Shell over the construction of a gas terminal in Rossport, County Mayo. Many of the ingredients of the Cohen-Raby argument are here: a supine sovereign state that has dismantled legislation to protect the people of Ireland and ensure that they receive a proper share of the proceeds from a transnational, democratic institutions ('Shell County Council' and 'An Bord Stampala') that have failed to do their job, a judiciary (the rule of law) that acts in the interests of an elite and politicians and religious leaders who are in thrall to the imperatives of globalisation. Yet despite all this they slowly and painfully build up a campaign that finally catches light and triumphs. One of the hard-won lessons that McGrath and Ó Seighin pass on from this episode is to do your homework, play it straight and trust people. Cohen doesn't do that.

–  Michael Wagstaff