Fall of Kobani would be symbolic setback for Obama's Syria strategy

It is not a particularly strategic location, the United States and its allies never pledged to defend it, and few people outside the region had even heard of it before this month.

But the symbolism of US-led air strikes failing to prevent Islamic State militants from swamping the Syrian city of Kobani could provide an early setback to US President Barack Obama's three-week-old Syria air campaign - far beyond its battlefield importance.

If Islamic State seizes full control of the city - which US officials acknowledge is possible in coming days - it could boast that it has withstood American air power. A US-led coalition has launched 50 strikes against militant positions around the city, most of those in the last four days.

Analysts said Islamic State would also be able to free up thousands of fighters to pursue territorial gains elsewhere in Syria and Iraq, such as Anbar province.

Islamic State militants are threatening to overrun the key province in western Iraq in what would be a major victory for the jihadis and an embarrassing setback for the US-led coalition targeting the group.

A win for the Islamic State in Anbar would give the militants control of one of the country's most important dams and several large army installations, potentially boosting their stockpile of weapons. It would also allow them to establish a supply line from Syria almost to Baghdad, and give them a valuable position from which to launch attacks on the Iraqi capital.

Were Kobani to fall to the militants, inevitable questions would arise over Obama's pledge to keep US ground troops out of the fight and the strength of his international coalition. Turkey, whose border abuts Kobani, has declined to join military action against Islamic State.