In 2001, following the events of 9/11, Putin called terrorism "plague of the 21st century"1 - a disease that strikes innocent victims unexpectedly and in a undifferentiated way. The act of terrorism seemed irrational and unforeseen in the eyes of modern democracies due to the failure of the collective memory of the international community. The states of the Western world were reinforced in what might be called a regulated 'Westphalian order' - a type of conventional relations between balanced and identifiable powers in which sovereignty is essential. But this outlook on the international system seems now and even then somehow biased: indeed, nation-states have already been challenged by non-state actors for a long time. As Alan G. Stolberg…show more content… Stolberg is interessant to the extent that it describes non-state actors such as terrorist groups as actor that are not governments. However, the term "terrorism" appeared for the first time - following the events of the period of Terror in 1798 - in the fifth edition of the French Academy’s Dictionary and referred to as a mode of state government by the use of terror4. Nowadays, the action of terrorism still relies on the use of terror but has changed ownership. Moreover, it relies more and more on the capabilities of other violent non-state actors such as crime organizations through multiple means. Furthermore, the issue of the proliferation of weapons of mass destruction is at stake with these transnational non-state actors. Since the end of the Cold War and the advent of a "new world order", the way is opened to that kind of other forms of confrontations. Thus, terrorism - the weapon of the weak to borrow from the story of David against Goliath - has become the spearhead of the struggle started by many armed groups around the new millennium. But more than domestic terrorism, today's terrorism has deeply mutated and definitely constitutes a transnational threat - "threats to the international system that cross state borders" Alan G Stolberg, , ‘Chapter 9: The International System in the 21st Century’, U.S. Army War College Guide to National Security Issues,: National Security Politcy and Strategy, Vol 2, No 5, (Carlisle, United States:…show more content… This terrible event gave an international credibility to the threat presented by the terrorist ends of Al-Qaeda as evidenced by the multilateral intervention in Afghanistan in 2001. The planning and the expertise demonstrated by the terrorist group set terrorism in all new level. A non-state actor ended up effectively affecting a powerful nation-state: this assertion underlines the paradigm shift from older form of international relation. As Hidemi Suganami put it "a new kind of war has emerged, in which the key participants are non-state entities" - placing himself in the line of General Sir Rupert Smith and its introduction of The Utility of Force. The reason of this shift is simple: the development of globalization while national boundaries still remain. Indeed, globalization has broaden the scope of possibilities violent state-actors have at their disposal. As non-state actors, their ambitions can exceed the boundaries of the state they are based in. Conversely, nation-states as powerful as they can be are limited by their boundaries which sovereignty cannot exceed. Control on these violent non-state actors is therefore hard to achieve, "since they are not territorial actors" but "enemies without an address" Ataman. That is how "rebellion becomes transnational" while nation-states are relatively confined within