CYIL 7 ȍ2016Ȏ ISLAMIC STATE, AN ACTOR THREATENING PEACE IN THE MIDDLE EAST states that these terrorist attacks should not be sporadic, isolated attacks, but rather they should be systematic in character. They base their view on the fact that such attacks are of such extent and intensity that they are comparable to armed attacks of a state. Ronzitti 52 writes in relation to the US air strikes in Syria that the right to self-defence is initiated in case of an armed attack of a state and /or an attack of a non-state actor – that is, also in case of an attack by the combatants of the Islamic state from their bases in Syria. On the other hand, some authors 53 refer to advisory opinions of the International Court of Justice on the Israeli West Bank of 2004, according to which Article 51 of the Charter recognizes the right to self-defence in case of an armed attack of one state against the other state. These authors understand the advisory opinion as a confirmation of the fact that self-defence is possible only among states . There are also contradictory opinions which claim that the Court did not say that that self-defence is possible only in case of an armed attack of one state against the other. 54 The authors of this paper share this second view. It is possible to remark that the International Court of Justice also stated in its advisory opinion that Israel exercises control over the occupied Palestinian territory and that the source of threats which justify the construction of the wall is within and not outside that territory . It is therefore a different situation from the UN Security Council resolutions No. 1368/2001 and 1373/2001, which were adopted after the terrorist attacks in the USA in 2001. Israel therefore cannot refer to these resolutions as reasons for the exercise of the right to self-defence. 55 The conclusions of the International Court of Justice can therefore rather be interpreted as if the Court wanted to express the opinion that for the exercise of the right to self-defence it is necessary the armed attack be from outside. Reference to the anti-terrorist resolution does not exclude the possibility of an armed attack from non-state actors. The consideration about self-defence in case of an attack by non-state actors is therefore ambiguous. The main issue is the problematic character of an intervention against such actors on the territory of a foreign state which does not agree with the intervention. Military interventions in Syria are conducted by only one side, by Russia. These are air strikes against the Islamic state which started at the end of September 2015. Russian president Putin announced that this constitutes Russian help in the fight against Islamists which was demanded by Syrian president Assad, with whose terrestrial forces these strikes will be coordinated. 56 Assad’s administration simultaneously announced 52 RONZITTI, Natalino.The Intervention against the Islamic State under International Law. International Relations and Security Network (ISN) 7 November 2014. 53 ANTONOPOULOS, C. cited in: BÍLKOVÁ, Veronika. Boj proti terorismu z pohledu ochrany lidských práv. Plzeň: Vydavatelství a nakladatelství A. Čeněk, 2014, p. 62. 54 Ibid . 55 ICJ. Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, 9 July 2004, ICJ Reports, 2004, 2004, par. 139. 56 Rusové bombardují islamisty. Právo 1. 10. 2015.