There was no shortage of debate on “fourth-generation” warfare when Donald Rumsfeld began his second tour of duty at the Pentagon in 2001 amid a buzz of enthusiasm for crafting the mobile and technologically adept military of the future. The grinding misery of America's embroilment in Iraq has long since removed Rumsfeld's personal lustre, but the theme of military modernization has survived. Though the Bush administration's failed attempt at a troop-light occupation has brought criticism of one feature of the modernization agenda, the war in Iraq has also encouraged thinking about how better to prepare the military for conflict with superficially weak but diffuse and adaptable enemies of the sort it presently faces.

Inspired most recently by the US campaign in Afghanistan – which with hindsight looks like a confidence-building enabler of the plunge into Mesopotamia – Adam Lowther seeks to contribute to this literature on the changing American way of war. He does so with a mixture of classical war theory and historical case studies designed to offer “lessons learned” of use in Iraq and beyond. To prepare the ground, he first provides a sweeping historical survey of military thought in both East and West, from the ancient Greeks and Romans through to the wars of the twentieth century. As well as technology-driven “generational” shifts in the nature of war, the author's chief theme, as his title suggests, is asymmetric conflict, wherein weaker opponents hope to foreshorten outside intervention by choosing tactics that play to their strengths, inflicting costs the intervener is ultimately unwilling to bear. He then offers detailed case studies of the US interventions in Lebanon (1982–84), Somalia (1992–94) and Afghanistan (2001–4) where asymmetry was a key feature.

In the first two cases, Lowther's key findings amount to an identification of shortcomings in what amounted to failed interventions: in both cases US forces withdrew after an unexpected infliction of casualties by the enemy shattered political support for the intervention. Foremost among these shortcomings he identifies poor human intelligence, deployment of insufficient force strength, insufficient investment of resources in “nation-building,” and an excessively “static” defence posture (i.e. waiting for trouble to come and find you rather than hunting it down pre-emptively). He appears more impressed by operations in Afghanistan where, poor intelligence and inadequate troop numbers notwithstanding, he judges that a better job was done of aggressively pursuing the enemy and winning popular support through investment in reconstruction.

Recent reports have cast some doubt on the efficacy and/or sustainability of the NATO-centred campaign against Taliban resurgence in Afghanistan, and suggest also that major corruption has hindered reconstruction. Readers are therefore likely to find themselves wondering if the long-term prospects in the Afghan case are as encouraging as they sometimes appear from Lowther's account. Given that several accounts of the Iraq occupation have emphasized the role of harsh, intrusive US military methods in alienating the populace and feeding the insurgency, there must also be a question mark over the implicit recommendation here of larger US forces pursuing more aggressive tactics to harass the enemy.

Such residual dilemmas suggest that Lowther's book may not provide uncontroversial lessons from history for the interventions of tomorrow. But that is perhaps to set the bar for success rather high. It displays impressive erudition in compressing the history of the study of war into manageable form, provides solid cases for consideration, and offers practitioners some useful food for thought. Even if it does not have all the answers, it still has plenty to recommend it to those trying to find them.