The United States has stepped up its military support for Syrian Kurdish militias fighting the Islamic State, efforts that have angered Turkey , a longtime ally and NATO member, which is now weighing new measures to contain the ambitions of the Kurds, including a buffer zone within Syria . Ankara sees the Syrian Kurds as a serious national security threat because of their links to Kurdish nationalists in Turkey , who have waged a decades-long insurgency against the Turkish state. So it has looked on with growing concern at the expanding cooperation between the Syrian Kurdish militias and the United States military in the fight against the Islamic State, also known as ISIS or ISIL. The United States now maintains extensive […]