This is the new, Spanish edition of Dr Ekaterina Stepanova’s book, originally published in English by Oxford University Press in 2008. The book was published as a special issue in a series «Cuadernos de Actualidad en Defensa y Estrategia» edited by the Argentinian Ministry of Defense. The preface to the Spanish edition is written by D-ra Nilda Garre, Minister of Defense. The book which was presented at the Argentinian National Defense College on 25 August 2009 challenges conventional thinking on how to understand and address terrorism in asymmetrical conflicts around the world. It views the combination of extremist ideologies and organizational forms of armed actors employing terrorist means as the main comparative advantage of such groups in asymmetrical confrontation with states (groups of states, international organizations) as the conventionally more powerful ‘system’ actors of higher status.