This book by Swiss historian Daniele Ganser can now be read online or downloaded for free as a .txt or .pdf file from:
http://www.scribd.com/doc/294202/Daniele-Ganser-NATOs-Secret-Armies-Operation-Gladio-and-Terrorism-in-Western-Europe(For the download option, you have to register at the site by giving an email address and creating a username)
Here is what the British author and academic Nafeez Ahmed said about this book:
The “strategy of tension” denotes a highly secretive series of interconnected covert operations conducted jointly by the CIA and MI6 largely in Western Europe during the this period. Well-documented by several respected historians, confirmed by official inquiries, and corroborated by former intelligence officials, the “strategy of tension” is one of those unsavoury moments in contemporary history that we don’t learn about in school, or even university.
My favourite book on the subject, and the most authoritative in my view, is Dr. Daniele Ganser’s NATO’s Secret Armies: Operation Gladio and Terrorism in Western Europe (2004). Published in the UK as part of the “Contemporary Security Studies” series of London-based academic press Routledge, Ganser’s study is the first major historical work to bring the “strategy of tension” into the mainstream of scholarship.
During the Cold War, indeed through to the late 1980s, the United States, United Kingdom, and Western European governments and secret services, participated in a sophisticated NATO-backed operation to engineer terrorist attacks inside Western Europe, to be blamed on the Soviet Union. The objective was to galvanize public opinion against leftwing policies and parties, and ultimately to mobilize popular support for purportedly anti-Soviet policies at home and abroad – most of which were really designed to legitimize brutal military interventions against nationalist independence movements in the “Third World”.
Ganser was a Senior Researcher at the Center for Security Studies in the Swiss Federal Institute of Technology, Zurich, before he moved to Basel University to teach history. Citing the transcripts of European parliamentary inquiries; the few secret documents that have been declassified; interviews with government, military and intelligence officials; and so on, Ganser shows how intimately the British were involved.
http://nafeez.blogspot.com/2007/05/strategy-of-tension.html