Operation Euphrates Shield

Operation Euphrates Shield (Turkish: Fırat Kalkanı Harekâtı) was an offensive by the Turkish Armed Forces and the Turkish-backed Free Syrian Army, which led to the Turkish occupation of northern Syria. Operations were carried out in the region between the Euphrates river to the east and the rebel-held area around Azaz to the west. The Turkish military and Turkey-aligned Syrian rebel groups, some of which used the Free Syrian Army label, fought against the forces of the Islamic State (IS) as well as against the Syrian Democratic Forces (SDF) from 24 August 2016. On 29 March 2017, the Turkish military officially announced that Operation Euphrates Shield was "successfully completed".

The Turkish president Recep Tayyip Erdoğan said on the first day of the operation that it was aimed against both the IS and Syrian Kurdish "terror groups that threaten our country in northern Syria". The objective to capture Manbij, under the de facto control of the AANES administration, that had been promulgated by the Turkish president at the end of February 2017 remained unfulfilled.

Northern Aleppo Governorate is a region of major strategic importance in the Syrian civil war, previously mostly held by the Islamic State (IS). For IS it was their only gate to the Turkish border. For the Syrian Democratic Forces (SDF), the Shahba region between the Euphrates River to the east and the Kurd Mountains to the west is the missing link to connect the cantons of the Federation of Northern Syria – Rojava. For Turkey, it is the path to its influence in Syria. The stage for the Jarabulus offensive was set by the previous Manbij offensive from June–August, which saw the SDF capturing the city of Manbij and its surroundings from ISIL and in the aftermath moving north. At the same time, Turkey-backed Syrian rebels fought the Battle of al-Rai to approach Jarabulus from the west.

According to an article published in The Independent, the Turkish objectives were to target ISIL, strike at the political and military power of the Democratic Union Party (PYD) and to consolidate its position in expectation of shifts towards more war or greater peace. Turkey's defence minister Fikri Işık said that "preventing the Kurdish PYD party from uniting Kurdish cantons" east of Jarabulus with those further west was a priority. In Ankara Turkish president Recep Tayyip Erdoğan said "at 4 am this morning, operations started in the north of Syria against terror groups which constantly threaten our country".

Before the operation, SDF forces including People's Defense Units (YPG) units were advancing on Jarabulus following their military victory over the Islamic State in Manbij. Both Manbij and Jarabulus are west of the Euphrates River, but Turkey wanted YPG forces to move back to the east of the river after the conclusion of the SDF's Manbij operation.

Turkey's action pitched its military against a force backed by its NATO ally, the United States. It was the first time Turkish warplanes struck in Syria since November 2015, when Turkey downed a Russian warplane, and the first significant incursion by Turkish special forces since a brief operation to relocate the tomb of Suleyman Shah, in February 2015.

Pro-SDF sources stated that Turkey had "an agreement with IS " to rescue it in Jarabulus from the SDF offensive. According to Hürriyet Daily News this report is believed by "many" in Washington and Turkey and it could pose serious problems for Ankara.

Reportedly, Turkey had prepared battle plans for the intervention more than a year prior. On 9 May 2016, a plan was reportedly proposed by the US, Turkey, Saudi Arabia, and Qatar to have the Nour al-Din al-Zenki Movement form a "Northern Army" to gather more than 3,000 fighters for the operation. The next phase was to transfer the fighters from Idlib to northern Aleppo through the Bab al-Hawa Border Crossing and the Azaz border crossing. This reportedly began on 13 May. However, the plan was delayed due to doubts from U.S. officials about the capabilities of the Syrian rebel forces that Turkey had recruited to fight with its military, opposition from the US-backed Syrian Democratic Forces, and the rift between Turkey and Russia that was not mended until early August 2016.