In the most classical way and a less than original strategy in International Relations, this research is about power, the sources of power, and power relations. However, the unit of analysis is all but classical; on the contrary, this is something which is still an unusual presence within the discipline: the mass media. This research, indeed, aims at understanding if, how, and why the news international television networks (and CNN in particular) had power over the political and military decision-making during NATO’s intervention in Kosovo and Operation Enduring Freedom. Having analysed the existing literature to clarify concepts and theories which explain media power during international conflicts, I advanced my criticisms and presented my hypotheses about media power, and its sources, in order to develop a theoretical framework on which I could ground the empirical part of the research. It has been clarified, therefore, that the international news networks have: a) Power over the political agenda; b) Power over the process (over timing of the decision making); c) Power over the selection of communication channels; d) Power over the choice of instruments. A complex set of different methods has been used, which leads to an essentially diagnostic case analysis. This is based on the examination of those processes which, through documentation and interpretation, would be considered as effects of media power. In particular, the presence of some different effects has been detected: Agenda Setting, Real Time Policy, Media Diplomacy, and what has been labelled Media War. Research methodology is a combination of qualitative methods of both data collection and analysis, varying for each supposed effect of media power. The most important data are transcripts from CNN, newspaper articles, press agency bulletins, memoirs, and texts of original interviews conducted with policy makers, journalists, and military officials. These texts have been considered both as sources of information and as text to be rigorously analysed through a particular method of text analysis, which is semiotics, in order show how meaning is constructed by different speakers.