With the defeat of Isis close, its opponents scent opportunity in the region. Can Kurdish forces win more autonomy?

As what remains of Islamic State crumbles, the would-be victors have started circling. In Mosul, Iraqi forces have begun preparing for peace in the city where the now-encircled marauders took root three years ago. Across the border in Raqqa, with five of its neighbourhoods under their control, Kurdish forces are contemplating what comes next for them and their cause.

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Day-after scenarios are rapidly being plotted by every group that has played a role in Iraq and Syria over many years of war and loss. Russia, the US and Iran are jostling for advantage across the swath of both countries held by the capitulating group. The prize is far more than who gets to claim the inevitable military victory over Isis. At stake, for all sides, is the future make-up of the region and a chance to shape it in their likeness.

The wish list of outcomes is broad and divergent. For Russia, there is the chance to establish a presence in the centre of the region, with political muscle and enhanced gas and oil interests. For Iran, a consolidated and potentially decisive role in both countries. And for the US – in the absence of a broader strategy – the chance to spoil its rivals’ plans.

Amid the great power struggles, others too have sensed opportunity in chaos. The Kurds of Iraq and Syria have made little attempt to hide the fact that the post-Isis vacuum marks a rare, potentially historic, moment.

In Iraq, the president of the largely autonomous Kurdish north, Massoud Barzani, has called a referendum on independence to be held on 25 September. In Syria, Kurdish forces raised by the US, and sent to oust Isis from one of its last two citadels, believe that their role can be parlayed into broader autonomy.

Across a dizzying battlefield that has devolved into a series of concurrent conflicts within the one war, Kurdish forces backed by the US are making steady gains in Raqqa. In Iraq, in the early phases of the fight for Mosul, the peshmerga played an important part in securing the city’s northern and eastern approaches.

The role they played in Iraq and continue to play in Syria is seen by both Kurdish factions as offering significant leverage in any negotiations. The view elsewhere is very different. Iraq and Turkey have said they would not support a break-up of Iraq, symbolic or otherwise, and have shown little enthusiasm for more than the current arrangements, which allow – begrudgingly in Baghdad’s case – the Kurds to sell oil taken from fields in northern Iraq through a pipeline they have built to Turkey.

The US has refused to support talk of Kurdish independence since the invasion to oust Saddam Hussein, wedding itself to the position that a united Iraq best serves its disparate peoples. Overriding the view are the explicit fears of regional allies that a break-up of Iraq along ethnic lines would directly threaten their own borders.

“That position won’t change,” said a senior US official. “It is not the time to be redrawing state boundaries, especially in Iraq and Syria. Such talk can only be advanced by broad regional consensus. And we are nowhere near that yet.”

Turkey, which has forged close economic ties with Iraqi Kurdistan as a means of maintaining the status quo, has been even more vehemently opposed to US backing for Kurdish groups in Syria, pointing to their ties to the Kurdistan Workers’ party, or PKK, with whom Ankara has fought a deadly four-decade insurgency inside its borders.

In the Iraqi Kurdistan capital of Erbil, the security chancellor of the region, Masrour Barzani, says Turkey has nothing to fear from the poll. “The referendum will shape the bilateral relationship between Kurdistan and the rest of Iraq,” he said. “We do not intend to change borders of neighbouring states. It simply formalises a delineated border between Kurdistan and the rest of Iraq.

“It’s time to accept that this model is not working. Iraq is already practically divided, and this vote will reflect what has already taken place. This referendum will be binding. It will give us a mandate to negotiate a peaceful settlement with Baghdad on terms that recognise the legitimate aspirations of our people.”

Baghdad also expects its share of the pie for the role its forces have played in recapturing cities they lost three years ago. There is little sign among the country’s leaders of a willingness to cede a large part of the country as the price of a victory. Nor is there a willingness to do business on touchstone issues such as Kirkuk or oil revenues.

“They think they won the war?” asked one senior parliamentarian in the Iraqi capital. “We have tens of thousands of martyrs, and they have 42. If there was a way to get rid of them and maintain what is ours, we would. But there’s not.”

In Syria, where US-backed Syria Democratic Forces (SDF) fighters are chipping away at Raqqa, having advanced through the north-east of the country and overrun Isis-held areas along the way, a direct clash between the Syrian regime and the US air force last week led to the downing of a Syrian jet to the south-west of the city.

“They were bombing our positions,” said an SDF spokesman, Talal Selo. “They attacked us three times very deliberately. They think that advancing against Isis from the south of the city should be their role.”

When the Raqqa campaign started on 6 June, Washington said there were 2,500 battle-ready SDF fighters. Since then, 15 have been killed, along with more than 300 Isis members.

South of Raqqa, the fight to eliminate what remains of Isis segues into a broader conflict. Iran has moved militia forces that it backs into the Euphrates river valley, an essential area of influence over the past 14 years. The effect of that has been to stymie US plans to move into the area from strongholds further south.

How to establish US influence in the area, and secure a legacy once Isis is defeated in Raqqa, has been consuming planners in Washington in recent weeks. One official told the Observer that Kurdish proxy forces should not think that their role in the war entitled them to a broader geopolitical role once it was over.

“Russia prised the Turks away from the Syrian opposition because it told [Turkish president] Erdoğan that it supported Syria’s territorial integrity. Assad wanted to hear that too. The Kurds need to realise that this isn’t going anywhere for them. When this is done, they need to go home.”