This article aims to analyze the effects of globalization in the State and its relation to the fight against terrorism. Firstly, I try to explain the characteristics and the limits within the State in a world increasingly interconnected and interdependent, this is, the progressive informality that is conquering of the world; the predominant formal character of the State and the consequences of this decoupling. Then, I attempt to analyze the new forms of terrorism and the main difficulties that States have in meeting the challenges related with International Security and Defense. I also set out the formal and informal mechanisms historically used by States in the field of Security.