As this American presidency stumbles towards its conclusion, there is an overwhelming liberal consensus on both sides of the Atlantic that George Bush has got it wrong about almost everything: declaring a “war on terror”; mismanaging Afghanistan; invading Iraq; identifying the security interests of America with those of Israel; deploying vast force as a substitute for policy, diplomacy, intelligence.

Philip Bobbitt is a quiet-spoken, boundlessly charming Texan, a nephew of Lyndon Johnson, who has spent much of his career as a law professor, with interludes serving at the White House. Although a lifelong Democrat, he is an impassioned supporter of much that Bush has attempted since 2001. In this huge volume, he argues that the West should indeed conduct a war on terror; that the Afghan intervention, though “incomplete”, was right and remains winnable; and that the Iraq war likewise.

He is haunted by apprehension about what terrorists in possession of WMD could do to our civilisation, and believes that a radical reform of international law is necessary to forestall them. He rejects the notion that terror is rooted in social ills or remediable political grievances. Pervading his argument is a warning: unless we change our expectations of swift and decisive victory on such battlefields as Afghanistan and Iraq, and reconcile ourselves to the necessity for very, very long hauls, the consequences for the West will be dire.

All this seems good for us to debate. If Bush overreacted, or rather misreacted, after 9/11, many other people have underreacted - as also after the London bombings in July 2005. We have eagerly embraced expert opinion, which tells us that it is harder than doomsayers suppose for terrorists to acquire nuclear weapons, or to weaponise biological agents. Yet it seems impossible to dispute that there are ingenious, energetic, lavishly funded people out there who wish to do us harm, and could sooner or later acquire horrible means. Bobbitt poses good questions that are hard to answer - for instance, if terrorism is rooted in Muslim grievances about western support for Israel or engagement in Afghanistan and Iraq, why are so few of those apprehended in the West for terrorist crimes Palestinians, Afghans or Iraqis ?

His last book, The Shield of Achilles, addressed the global transition from nation to market states. Here, he returns to this theme. On the one hand, he perceives citizens' weakening loyalty and gratitude towards their own governments and institutions. On the other, he sees enemies who admit no allegiance save to the pursuit of terror, and are committed to the fantastic and unattainable adoption of a worldwide caliphate. The market state, he says, empowers the terrorist as much as the individual at the expense of the forces of legitimate authority and order. It is vastly more difficult to mobilise and sustain democratic consent for anti-terrorist laws and security measures than for national defence in a conventional war, in which everybody can see the enemy's armies at the gates, his bombers overhead.

Pervading Bobbitt's book is a deep moral belief in the rightness of the West's cause which is at odds with much popular instinct. I would venture to suggest that Osama Bin Laden inspires less hatred in our society than does George Bush. In our perverse, idiotic way, we admire Bin Laden for making the American military machine look ridiculous, while we deplore Bush because we share the embarrassment of his leadership and the burden of his follies.

Such sentiments are an indulgence that may soon become unaffordable. To possess any hope of defending ourselves against evildoers - and evil the terrorists assuredly are - we need to possess faith in ourselves. Many people, however, are deeply troubled by America's unqualified support for Israeli expansionism in Palestine, which Bobbitt scarcely mentions. We perceive Muslim extremism as driven by a readily comprehended, if not easily assuaged, cultural and economic resentment towards the West.

We do not trust the governments of America or Britain to display the supreme wisdom which alone could justify granting them the far-reaching legal powers which the author advocates. I believe that there will be further terrorist atrocities, following which the American and British publics will accept - indeed, probably demand - new curbs on civil liberties. But it seems right that we should adopt a policy of reluctant proportionate response, rather than draconian precautionary initiative.

Bobbitt does not believe we can afford to act so cautiously, when Al-Qaeda and its many offshoots are committed to creating a permanent state of terror. Beyond the big issues, his book addresses numerous subordinate points that deserve attention. The author is surely right, that the organisation and agendas of western intelligence services need radical reform. Air travel will remain a nightmare until we recognise the absurdity of subjecting every passenger to equally intense security screening, and prioritise plausible terrorist suspects. So-called “profiling” enrages civil libertarians, but it is obvious that, for instance, an elderly white woman is unlikely to be a suicide bomber.

I share wholeheartedly Bobbitt's belief that the armed forces must be reconfigured, to provide effective civil support in the wake of conflict. The old US army view that “we don't do nation building” has been a significant contributory factor to failure in Iraq. The first duty of soldiers is to fight, not kiss babies. But every man who has served in Iraq or Afghanistan recognises the indispensability of committing engineers, doctors and above all policemen behind the tanks. We shall never get military interventions right anywhere in the world, until we commit stabilising forces to secure societies.

One factor not mentioned in the book, but that seems critical, is the contrast between, say, 1945 Germans and Japanese, who were defeated and knew it, and modern Iraqis and Afghans, who are instead told that they are victims who have been liberated. Liberated people cannot be casually shot if they break rules, as were the vanquished of 1945. They are encouraged to have expectations much like those of western electorates, and respond with appropriate disgust if these are disappointed. Iraq's politicians display an intransigence about compromise with each other that would have been unthinkable among the defeated of the second world war, and which contributes mightily to the difficulties of creating a workable society today.

Many of us believe that terrorism (asymmetric warfare) is inevitable in an age when American military power is invincible against conventional forces, and that it acquires a tragic moral legitimacy in places where no democratic means exist of remedying grievances. “Give us F-16s,” a Palestinian is alleged to have said, “and we shall no longer need suicide bombers.” The author's pleas for changes in international law are unlikely to be heeded, if these appear measures further to empower the strong against the weak.

I put down this challenging, complex book still believing that terrorism is best fought by sustained, convincing diplomacy, intelligence, police and special forces operations, rather than through military initiatives or dramatic changes in national polities. But the author obliges us to think about all manner of issues vital to the security of the western democracies, when too many people still cling to the hope that each terrorist horror will prove the last. Terror and Consent: The Wars for the 21st Century by Philip Bobbitt

Terror and Consent by Philip Bobbitt
Allen Lane £25 pp688

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