Operation Olive Branch
On 20th January 2018, the Turkish military started to attack the Kurdish-populated region of Afrin in Syria (“Operation Olive Branch“). With its letter to the Security Council of 22nd January 2018, Turkey justified this action as self-defence in terms of Art. 51 UN Charter. The relevant passage of the letter is: “[T]he threat of terrorism from Syria targeting our borders has not ended. The recent increase in rocket attacks and harassment fire directed at Hatay and Kilis provinces of Turkey from the Afrin region of Syria, which is under the control of the PKK/KCK/PYD/YPG terrorist organization, has resulted in the deaths of many civilians and soldiers and has left many more wounded.” (UN Doc. S/2018/53; emphasis added). Two elements are troublesome in this official Turkish justification.
Non-state armed attacks?
First, it is controversial whether armed attacks of the YPG, a non-state actor, suffice to trigger self-defence in terms of Article 51 UN Charter and underlying customary law. The current law (both Charter-based and treaty-based) is in flux, and still seems to demand some attribution to the state from which the attacks originate. (See for a collection of diverse scholarly opinion, ranging from “restrictivists” to “expansionists”: Anne Peters, Christian Marxsen (eds), “Self-Defence Against Non-State Actors: Impulses from the Max Planck Trialogues on the Law of Peace and War”, Heidelberg Journal of International Law 77 (2017), 1-93; SSRN-version in Max Planck Research Papers 2017-17).