The United States now has the power to spy on communications world-wide. Whether over fixed or mobile phone, fax or internet, no secret is safe from them thanks to Echelon network. Four billion communications are intercepted and categorised daily in the world for the Americans and the British. For some years, Duncan Campbell , a journalist and physicist specialising in communications, has maintained a crusade against Echelon, a surveillance network tracking commercial satellites in order to intercept their communications. He recently made waves at the European Parliament with a report in which he outlined in detail the mode of operation and objectives of Echelon, a post-war joint effort by the Americans and British. Such a network raises the issue of confidentiality of diplomatic exchanges, as well as of economic and industrial espionage. To what extent have European enterprises been prejudiced? What are the implications of this alliance between British and Americans against Europeans? In order to decipher the issues at stake in this new all-out war, Temps Présent has undertaken a fascinating investigation in the United States, Brussels, England and Switzerland. Among the many personalities putting forward their views are Charles Pasqua, members of the French State Security Department, and journalists who have for years been investigating the different aspects of this issue.