Islamic State's defeat in Kobani and other recent setbacks in Syria suggest the group is under strain but far from collapse in the Syrian half of its self-declared caliphate.
Islamic State's high-profile defeat by Kurdish militia backed by U.S.-led air strikes capped a four-month battle that cost Islamic State 2,000 of its fighters, according to the Syrian Observatory for Human Rights, which tracks the war.
Further from the spotlight, Islamic State has also lost ground to Syrian government and Syrian Kurdish forces elsewhere. Its foes have noted unusual signs of disorganization in its ranks, while reports of forced conscription may indicate a manpower problem as the group wages war in both Syria and Iraq.
There is a long way to go before the tide turns decisively against the group in Syria, where it has faced less military pressure than in Iraq. Islamic State still has a firm grip over its Syrian stronghold in Raqqa province and territory stretching all the way to the other half of its caliphate in Iraq.
The group faces no serious challenge to its rule over those Sunni Arab areas, where it has violently crushed all opposition.
It may yet respond to the Kobani defeat by opening new fronts in Syria. And its capacity to wage psychological warfare was amply demonstrated by this week's video showing the group burning to death a captive Jordanian pilot.
Yet the Kobani defeat marks the first significant setback for Islamic State (ISIL) in Syria since the rapid expansion of its territorial grip there last year following its capture of Iraqi city of Mosul in June.
Islamic State had paid "a very heavy price in Kobani", said Lieutenant Colonel Thomas Gilleran, a U.S. military officer and media official in the U.S.-led alliance against Islamic State.
"Outside of Kobani, there are admittedly many areas in Syria where ISIL is uncontested by opposing ground forces. However, there are multiple areas as well where they are indeed under pressure by Syrian Regime Forces, Kurdish elements, and other opposition groups within Syria," he told Reuters.
Adding to the pressure, Islamic State's finances are believed to be under strain because of a global collapse in oil prices. The group has bankrolled itself partly by selling oil in the areas it controls.
Beyond Kobani, Islamic State has recently lost territory to Syrian government forces in an important battle near an air base in Deir al-Zor province, the Observatory has reported.
It has also lost ground to government and Kurdish forces in the northeastern Hasaka region, a province bordering Iraq, according to the Observatory and a Kurdish official.
In the latest advances there, the Syrian military seized 16 villages from Islamic State, killing large numbers of its fighters, the Syrian state news agency SANA reported on Friday.
The jihadists are hunkering down in defensive positions and their attacks in the area over the past month have been unusually disorganized, said Kurdish official Nasir Haj Mansour of the Kurdish defense authority in the northeast.
"This doesn't mean it lost all of its strength. But it is not at the same level of ferocity as before," he said, speaking via Skype from the area.
The group had deployed its full arsenal in the Kobani battle, including suicide bombers in armored personnel carriers, according to the Observatory. U.S. air support and Iraqi peshmerga Kurdish fighters were crucial in helping the Kurdish YPG militia win back the town.
Kobani was of little strategic significance. But the battle - reported extensively by international media from the adjacent Turkish border - became a focal point for the fight in Syria.
Two Islamic State fighters reached via Skype said the group's withdrawal from Kobani was tactical.
The group has been under greater pressure in Iraq, where it still holds Mosul and much of Anbar province but heavily armed peshmerga have regained considerable ground elsewhere.
One of the fighters said recent attacks in Egypt showed it was broadening its reach.
"Some units of the Islamic State army move from Syria to Iraq and vice versa," said the fighter, who was speaking from Raqqa and did not give his name in a Skype interview.
The U.S.-led air campaign has struck Islamic State fighters and equipment moving from Syria to Iraq as well as targets in Hasaka and elsewhere. Jordan said it had sent tens of fighter jets to pound Islamic State targets in Syria on Thursday in what it said was just the beginning of its retaliation for the killing of the pilot.
The Observatory described it as the most intense bombardment by the U.S.-led coalition since the start of the year, but it is widely acknowledged that it will take ground forces to roll back Islamic State.
In Deir al-Zor province, which links Raqqa to Iraq, the group's grip has tightened, said one rebel leader whose mainstream group operated in the area before Islamic State expelled it.
Yet pockets of resistance have emerged, with small groups staging ambush-style attacks against its fighters.
The government still controls a major air base. Its forces, backed by allied militia, recently took ground from Islamic State around the base.
Someone who took part in recent battles against Islamic State in Deir al-Zor described pointless suicide attacks by at least six of its fighters against impenetrable fortifications. He said they lacked a command structure.
"We were puzzled and entertained," said the combatant, who was speaking privately. "You can not just blow yourself up at a barricade."
Meanwhile, the group has launched a campaign of forced conscription in Deir al-Zor, the rebel leader and the Observatory said. "It shows a shortfall," said Rami Abdulrahman, the Observatory director.
The course of the battle in Syria, as in Iraq, will hinge on whether Islamic State's enemies can defeat it in Sunni Arab areas where it is most entrenched.
To this end, the United States is planning to arm and train members of the mainstream opposition to President Bashar al-Assad. But it has yet to start recruiting and there are many questions over how will proceed: the non-jihadist opposition groups are weakest of all the parties in the conflict.
Washington has shunned the idea of cooperation with Assad, though there is indirect cooperation as they share the same air space.
The Kurdish YPG militia, already a U.S. partner in the fight against Islamic State, has shown grit fighting Islamic State but its potency will likely diminish beyond the Kurdish areas.
A senior Western diplomat said the significance of Islamic State's recent setbacks should not be exaggerated, but added: "There’s no doubt that the heady days of ISIS are over."
Left to its own devices in Sunni Arab areas, Islamic State will be able to regroup. "Islamic State is on the defensive, it is disorganized, like drops of mercury that have been separated. But they can come back together again," said one diplomat.