Since the events of 11 September 2001, insurgency - an organised movement aimed at the overthrow of a constituted government, the pursuance of specific political objectives or the control of a specific territory through the use of subversion and armed conflict - has moved into academic focus once again, and insurgency and terrorism now top the international security agenda. Although the demise of conventional (typically interstate) warfare has been considerably exaggerated in recent years, there is no question that low-intensity, unconventional insurgencies have become the dominant form of conflict, and seem likely to remain so for some time. This book is itself recognition of that reality.