Long considered the masters of counterinsurgency, the British military encountered significant problems in Iraq and Afghanistan when confronted with insurgent violence. In their effort to apply the principles and doctrines of past campaigns, they failed to prevent Basra and Helmand from descending into lawlessness, criminality, and violence. By juxtaposing the deterioration of these situations against Britain's celebrated legacy of counterinsurgency, this investigation identifies both the contributions and limitations of traditional tactics in such settings, exposing a disconcerting gap between ambitions and resources, intent and commitment. Building upon this detailed account of the Basra and Helmand campaigns, this volume conducts an unprecedented assessment of British military institutional adaptation in response to operations gone awry. In calling attention to the enduring effectiveness of insurgent methods and the threat posed by undergoverned spaces, David H. Ucko and Robert Egnell underscore the need for military organizations to meet the irregular challenges of future wars in new ways.