Turkey launches ground assault

ANKARA, Turkey — Turkey on Wednesday launched its first major ground assault into Syria since the country’s civil war began, sending in tanks and special forces backed by U.S. airstrikes to help Syrian rebels retake a border town from Islamic State militants.

The surprise incursion to capture the town of Jarablus was a dramatic escalation of Turkey’s role in Syria’s war. But its objective went beyond fighting extremists. Turkey also is aiming to contain expansion by Syria’s Kurds, who are also backed by the United States and have used the fight against IS and the chaos of the civil war to seize nearly the entire stretch of the border with Turkey in northern Syria.

That raises the potential for explosive frictions between two American allies. U.S. Vice President Joe Biden flew into Ankara hours after the offensive, and he backed Turkey with a stern warning to the Kurds to stay east of the Euphrates River, which crosses from Turkey into Syria at Jarablus.