THE image of Ché Guevara, with beard, beret and bandana, remains the icon of guerrilla war. Ché argued that a band of revolutionaries could be the focus for insurrection on a wider scale. Revolution, he said, could emerge from guerrilla warfare.

Ché’s ideas met their nemesis — and their author his death — in Bolivia in 1967. But his ultimate failure has not prevented us from associating the use of guerrilla warfare with “regime change”.

President Saddam Hussein’s purpose now is the very opposite: it is to prevent regime change. Moreover, his tyrannical regime would seem to be the sort most vulnerable to the use of guerrillas. It is highly centralised, brittle and unpopular.

Guerrilla warfare demands the decentralisation of authority and relies on the determination, ruthlessness and, above all, independence of subordinates on the spot. Possibly the most successful guerrilla leader of the 20th century was Mao. As a more orthodox Communist than Ché, Mao believed that revolution sprang from economic and political conditions, concluding that the strength of the guerrilla depended on his support from the people.

The seeming improbability of Saddam resorting to guerrilla warfare is compounded by the geographical conditions. Guerrillas need places to hide, and they favour terrain that hampers the movement of vehicles. The jungle of Malaya or Vietnam, or the mountains of the Balkans or Afghanistan — all provide more obviously “bandit” country than Iraq.

Between 1941 and 1942 Rommel deemed the desert the ideal environment for manoeuvre warfare, where conventional forces could face each other in what some romantic spirits dubbed “a war without hate”.

But guerrilla war is a means, not an end. There cannot be a war on guerrilla war any more than there can be a war on terrorism. As Mao recognised, guerrilla warfare is a tool of particular attraction to the weaker side. The attraction for the weaker power is that it neutralises the advantages of strong conventional armed forces. In 1941 Stalin responded to Hitler’s invasion of the Soviet Union by mobilising partisans in the rear of the advance: an army’s logistical tail tends to be more vulnerable than its teeth.

Neither the Americans nor the British should be surprised: the armies of both nations have spent much of the past decade pontificating about “asymmetrical” warfare, in which the other side elects not to meet like with like. Some theorists predict that armies themselves will become redundant, that in the 21st century armed conflict will become the business of the guerrilla, terrorist and partisan.

Ché still has a point, however. There could be political consequences from Iraq’s adoption of guerrilla war. Saddam might undermine his own authority.

The Iraqi state appears more cohesive than America hoped. An allied strategy that aims to distinguish between combatant and non-combatant will be very hard to implement if guerrillas are mixed in with civilians.

As defenders of a sovereign state against invasion, they will not be in breach of the laws of war. And over-reaction by the coalition forces, born of frustration and surprise, could drive Saddam and his people closer together. It could also rob the war of its legitimacy in the eyes of the American and British electorates.

• Hew Strachan is Chichele Professor of the History of War, University of Oxford

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