CEYLANPINAR, Turkey — Last week, I traveled to Turkey’s border with Syria. I was planning to cross into the Kurdish-controlled northeast to find out how the country’s most influential Kurdish group, the Democratic Unity Party (PYD), was running the string of towns and villages that fell under its control last summer.

I would have to cross into Syria illegally because Turkey’s formal border crossings with the Kurdish region remain sealed. My destination was the PYD-controlled town of Ras al-Ain, or Serekaniye in Kurdish, that stands opposite Ceylanpinar on the Turkish side. Colleagues who had used smuggler routes to get in assured me that I would sail through. But when I arrived in Ceylanpinar, I learned that the trip across included wiggling my way through barbed-wire fencing and risking being spotted by trigger-happy Turkish border guards. I dropped the idea, deciding instead to investigate widespread claims that Turkey is propping up Syrian rebels in a little-reported proxy war against the PYD.

The PYD is the Syrian franchise of the Kurdistan Workers Party, the rebel group known as the PKK that has been fighting on and off since 1984 for Kurdish autonomy inside Turkey. It is, therefore, not surprising that Turkey is nervous about the PYD’s gains.

I started off in Ceylanpinar, a shabby, nondescript town with a mixed population of Arabs and Kurds. Before Syria’s civil war erupted, Ceylanpinar was best known for a gigantic farming complex called TIGEM and its free-roaming herds of gazelles. These days, Ceylanpinar is making headlines with horror stories of locals being wounded by stray bullets and shells fired from Syria. At least four residents have died since fighting broke out in November between Syrian rebel forces and the PYD’s armed wing, known as the People’s Defense Units, or YPG.