Turkish Armed Forces (TAF) carried out ‘Operation Euphrates Shield’ for 216 days from August 2016 to March 2017 in the triangle between Azaz, Jarablus and al-Bab in northern Syria. Thanks to this military operation, Turkey cleared Daesh from the region and halted the risk of the PYD/YPG exercising control of the Syrian side of the shared 911km border by wedging itself between two PYD/YPG controlled areas. In addition, some displaced Syrians voluntarily returned to this region from Turkey, which currently hosts around 3.5 million Syrian refugees — more than any other country.
In line with this previous operation, the TAF launched ‘Operation Olive Branch’ on 20 January 2018 in Afrin, which has been controlled by the YPG. In its letter to the UN Security Council (UN Doc. S/2018/53), Turkey justified this operation on the basis of self-defence and various Security Council resolutions calling on Member States to fight terrorism.
Since the indicated UN Security Council resolutions do not explicitly authorize the cross-border use of force, Turkey’s reliance on it as a justification of its extraterritorial military operation is unacceptable in international law. As far as I see in legal discussions, there is no dispute over this. However, the question of whether Operation Olive Branch can be justified on the basis of self-defence has brought with it some controversy.
According to both Article 51 of the UN Charter and related customary international law, occurrence of an ‘armed attack’ is required for the activation of the inherent right of self-defence. The ICJ identified ‘scale and effects’ as the criteria that ‘distinguish the most grave forms of the use force (those constituting an armed attack) from other less grave forms,’ but has not specified indicators of these criteria (Nicaragua judgment, 1986, para. 191). It should be noted that the scale and effects criteria have nothing to do with numbers. Rather, it is a legal assessment depending on facts and circumstances at hand. Read the rest of this entry…