MESOP BACKGROUNDER : Fighting Escalates on Turkey-Syria Border, Endangering U.S. Forces

By Margaret Coker – WALL STREET JOURNAL  – 28 August 2016 – ISTANBUL—Tensions are escalating between Turkish armed forces and Syrian Kurdish rebels after the death of the first Turkish soldier involved in the newest battlefront of the Syrian war, a development that could further endanger U.S. forces in the area and complicate their mission to vanquish Islamic State.Turkey’s military stepped up its bombardment deeper into Syria with airstrikes and artillery strikes on Sunday after a Turkish soldier died earlier and three others were wounded earlier in the weekend when their tank unit came under attack by Kurdish rebels opposed to Turkey’s military operation. Turkish military sources said they have killed at least 25 “terrorists,” a reference to Kurdish fighters from that militia, known as the YPG.

Meanwhile, Syrian monitoring groups reported that at least 70 people were killed this weekend, most of whom were civilians, in the Turkish operations. Turkish officials didn’t comment on the reported civilian death toll, except to say that commanders are taking all necessary measures to protect noncombatants. It wasn’t possible to independently verify the Syrian casualty figures or the identities of those killed.

There was no immediate comment from U.S. officials about the escalation of fighting between the two sides—both of which receive American military support. It was unclear what part the U.S.-led coalition against Islamic State, of which Turkey is a member, played in the air campaign this weekend.

The clashes underscore the complexity of the U.S.-led international coalition campaign to reverse Islamic State’s territorial hold in Syria and the dangers faced in that mission. American special operations forces are embedded with the YPG and earlier this month helped them oust Islamic State from the town of Manbij, less than 20 miles from Saturday’s hostilities. In general, those U.S. special operations forces have close contact with their Turkish counterparts, and they rely on Turkey for their rear supply lines, according to people familiar with the situation.

The U.S. also supports the Turkish-led campaign launched last week to clear Jerablus of Islamic State positions and mop up any fighters that escaped Manbij, which is approximately 20 miles further south from the Turkish border.Turkish officials have said the timing of Operation Euphrates Shield was related to the fact that the YPG had broken a promise given to the Americans and Turks that the group’s units would withdraw from Manbij once it was liberated from Islamic State and allow local Arab-majority inhabitants to control the area. Instead of retreating to the east side of the Euphrates River outside Manbij, YPG in recent weeks has moved to expand westward in a new land grab, according to U.S. and Turkish officials.

Turkey considers the YPG to be a terrorist group and has a declared national security objective to prevent the YPG from linking up its disparate territorial holdings in Syria into a larger autonomous region. Turkey sees the YPG as an armed affiliate of its own domestic Kurdish militant group known as Kurdistan Workers’ Party, which has been fighting Turkish security forces for decades with the aim of achieving its own autonomous ethnic state.Turkey wants to install the friendly Arab rebels fighting in its current operation along the Manbij-Jarablus corridor as a buffer against Kurdish groups. An estimated 1,000 Syrian Arab rebels are working with Turkey, which has at least 380 soldiers and 40 tanks inside Syria, Turkey handed over control of the border town of Jarablus to local Arabs after successfully ousting Islamic State from there last week [eds Thursday].

On Saturday, some of the Syrian Arab units fighting under Turkish support said they were trying to seize a number of villages south of Jarablus when clashes with rival YPG units broke out. Clashes reportedly were fiercest around the village of Amarneh, around 5 miles south of Jarablus.Turkey’s armed units were supporting Saturday’s push when two tanks came under attack by YPG fighters armed with antitank rockets around 4 miles south of Jarablus, according to Anadolu. One soldier was killed and three others wounded, it said. It didn’t give any more details about the location of the attack.

Syrian groups who monitor fighting and civilian death tolls reported casualties on at least two battlefronts south of Jarablus as a result of the weekend clashes.Aleppo24 said that at least 28 civilians died in Turkish airstrikes, including people in Amarneh and a family from the neighboring village of Saressat. It also said that at least 19 fighters had been killed.

A second monitoring group, the Syrian Observatory for Human Rights, said at least 70 civilians were killed and wounded in Turkish airstrikes and shelling in the village of Jab al-Kousa, more than 8 miles south of Jarablus.Turkish officials didn’t respond to questions about locations of their airstrikes inside Syria or how many bombing raids were carried out. The state news agency reported that the Turkish Military Joint Special Task Forces and coalition airplanes targeted on Saturday an ammunition depot, barracks and a command center used by “terror groups” south of Jarablus.

A statement from Turkey’s military, reported by Anadolu, said that the offensive was being carried out in accordance with international law and the United Nations’ mandate of self-defense. Turkey has suffered several terror attacks at home this year believed to have been carried out by Islamic State and the PKK.

—Thomas Grove and Yeliz Candimir in Istanbul and Raja Abdulrahim and Noam Raydan contributed to this article.

Write to Margaret Coker at margaret.coker@wsj.com