Mr. Erdogan threatened last month to carry out a major cross-border operation into Syria to rout the Syrian Kurds who took control there from ISIS. Turkey conducted previous missions into Afrin and Jarabulus west of the Euphrates River.
American officials expressed skepticism that the Turkish military could sustain such an extensive and complicated operation into northeastern Syria, but worried that any Turkish invasion would wreak havoc with American counterterrorism goals and its relations with a NATO ally.
Led by James F. Jeffrey, the State Department’s special representative for Syria, and Gen. Joseph F. Dunford, Jr., the chairman of the Joint Chiefs of Staff, the two countries quickly worked out several steps to defuse tensions and focus on a 75-mile-long buffer zone between Tal Abyad and Ras al-Ayn, which the two sides agreed to and the Pentagon calls “the security mechanism area.”
The two militaries established a joint operations center in Ankara. They have conducted four joint reconnaissance flights over the area, including one on Thursday. And last weekend, American and Turkish troops conducted their first joint ground patrol.
In a sign of how diplomatic sensitivities are affecting the messaging behind these operations, the military’s news release about the first ground patrol showed one photograph with a Turkish vehicle in the lead and another with an American vehicle in the lead.
On Thursday, the Pentagon’s European command, which deals with Turkey, said that Lt. Gen. Stephen M. Twitty of the Army, the European command’s deputy commander, and Lt. Gen. Thomas Bergeson of the Air Force, Central Command’s No. 2 officer, had met with their Turkish counterparts to discuss future support for the combined joint operations.
“You can see the progress,” Col. Myles B. Caggins III, a spokesman for the American-led coalition overseeing operations in Iraq and Syria, said in a statement on Thursday, noting the delicate balance between addressing Turkey’s “legitimate security concerns” and the coalition’s efforts to combat ISIS.