If on occasion Bobbitt’s ideas sound naïve, he is equally capable of startling insights. His distinction between states of terror and states of consent is illuminating when applied to the question of sovereignty. He suggests that other states may lawfully intervene against such a “state of terror” to halt proliferation of WMD, genocide, international terrorism or to forestall a humanitarian catastrophe ignored by the regime. Bobbitt’s doctrine of sovereignty – as the exclusive attribute of a state of consent, but denied to states of terror - would justify pre-emptive intervention not only in Bosnia, Kosovo, Afghanistan and Iraq, but in Iran, Syria, North Korea, Gaza, Sudan, Zimbabwe and many other “states of terror”. He wants international law reformed to recognise the circumstances in which states are entitled to sovereignty – otherwise, as he admits, rogue states might exploit his doctrine to seek pretexts for aggression. Though he does not make the comparison, Bobbitt’s theory of sovereignty is not so very different from neoconservatism, which argues that democracies never launch wars of aggression against each other, and that it is therefore in America’s national interest to promote democracy and fight tyranny.

Bobbitt concludes this alarming but never alarmist book with A Plague Treatise for the Twenty-First Century. In such plague treatises, medieval physicians tried to explain to their contemporaries epidemics that they could not possibly diagnose correctly, let alone cure. Bobbitt concedes that he is groping for the answers. His analysis of the wars against terror includes the eloquent admission that “we can only know an epochal war for certain when it is past, and that past is, for the present, deep in our future”. Not even Professor Bobbitt can predict future plagues, but he is sure that if and when al-Qa’eda is eradicated, it will be succeeded by new terrorist threats. He sees “the Islamist flu” as an opportunity to build up our immune systems: our alliances and laws, always seeking consent for each step. The failure to seek consent is his most severe indictment of the Bush administration – though not altogether a fair one. (Does Bobbitt really think that putting terrorists in “an offshore penal colony” was done without consent in the aftermath of 9/11? It was only much later, after the Iraq war, that public opinion turned against the use of Guantanamo.)