“The Kurds have no friend but the mountains,” as the old saying goes. Yet there are few mountains in Northern Syria, where the Kurdish People’s Protection Units (YPG) and Women’s Protection Units (YPJ) formed a coalition with Arab militias called the Syrian Democratic Forces to fight the Islamic State in Iraq and Syria (ISIS).

The U.S. government resisted involvement in another protracted war in the Middle East, but relented as ISIS spread across the region. U.S. military airstrikes helped prevent Erbil from being overrun in Kurdistan, and then helped the YPG and YPJ secure a decisive victory in Kobani.

While America stumbled in Syria numerous times, a reliable ally was found in the Kurdish enclave in Northern Syria, a region the Kurds call Rojava. With ISIS launching external attacks in Europe and the United States—as well as attempting to establish affiliates elsewhere in the Middle East, Asia, Africa, and Afghanistan—the destruction of the Islamic State and their de facto capital, Raqqa, become a priority. As time went on, U.S. Special Operations soldiers were deployed to Rojava in increasingly numbers along with conventional forces.

Wedged between the Syrian regime, ISIS, and rather hostile governments like those of Turkey and the Kurdish regional administration led by Kurdistan Democratic Party, the United States became a security guarantor to Rojava. If Turkey or the Syrian regime invaded, they would almost certainly come into conflict with American troops and suffer at the hands of American airstrikes—as one Russian paramilitary group found out the hard way. Fears persisted among the Kurds that America’s relationship with them is simply one based on national interest rather than friendship.