Currently, Europe has to face new risks and threats, including terrorist attacks, illegal migration, and hybrid warfare that transcend the common security aspects and have further roots beyond its borders, in unsolved hot spot areas, like Eastern and Southern neighbourhood. Today rapid developments in the political and economic fields made terrorism a common problem for all the countries in the world. This is also true for European countries because, with the Madrid bombing of the Atocha Rail Station, where, for the first time in the history of terrorism, two organizations were involved together (Al Qaida and ETA) in committing a violent action, we can speak about the internationalisation of terror and the shift of its political objectives towards those nations supporting the United States in the International War on Terror. Since the 2014 Ukrainian crisis and Syrian conflict, including here military actions to counter the Salafi Jihadist militant group and alleged former Al Qaida affiliate in the Islamic State of Iraq and Syria (ISIS), a period of increased Islamic terrorist activity has taken place in Europe, often referred to as the Wave of Terror in Europe. Terrorists employed a wide range of tactics to support implementation of their overall strategies. In Europe, as we saw in the past events, terrorist organisations have mostly been employing old tactics such as bombing, arson, assassination and suicide attack to achieve their goals. The big issue for terror in Europe is the mix of some of these classical acts with new methods including the use of computer devices, driving transportation means against crowds, shooting and stabbing their targets, in order to transmit proposed messages. The European security context forced more and more European states to take “hard” measures for eliminating the danger of those terrorist organizations. A lot of books have been written and many analyses have been made since the 90s. However, the terrorists modify their tactics and weapons according to new conditions. Moreover, they co-operate with each other and gain a more Mafia like characteristic. Even, terrorist organizations and other crime organizations are going faster than the sovereign countries in the field of cooperation. Consequently, the terrorist organizations, instead of being annihilated, gain more power, with every countermeasure.