Iraqi Kurds run the risk of armed conflict with government forces and alienating neighbors if they push ahead with a proposed referendum on independence, according to a senior adviser to Turkey’s president.

Leaders of the semi-autonomous and oil-rich Kurdish region in Iraq’s north have for years flirted with a complete break from Baghdad’s rule. They renewed the calls after a sweeping 2014 offensive by Islamic State routed the Iraqi army, bringing the extremists to the Kurds’ borders. The plan for a Sept. 25 plebiscite -- to be followed by another for a new parliament and president on Nov. 6. -- drew the ire of Iraq’s government, the U.S. and Turkey, which worries sovereignty would encourage its own Kurdish insurgents.

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“The referendum is a prescription for deepening the area’s problems,” Ilnur Cevik, who advises Recep Tayyip Erdogan on foreign policy, said in an interview on Wednesday. As well as the potential for war with Iraq, “it would also alienate Turkey, Iran, all those who support the Kurds,” he said. “They will say there’s ‘a Kurdish pocket in the heart of Arab land,’ and they will oppose it.”

Sunni power Turkey has enjoyed closer ties to the Kurds than with the Shiite-led central government in Baghdad, which is backed by Iran, providing a key route to market for the Kurdish oil industry. But the chaos that could follow the break-up of OPEC’s second-biggest oil producer, and Turkey’s domestic security concerns, mean it has opposed Kurdish statehood.

‘Lost Hope’

During the 2003 U.S. invasion to topple Saddam Hussein, Turkey came close to sending troops into northern Iraq to prevent the Kurds extending their borders to oil-rich Kirkuk, home to many ethnic Turkmen. Erdogan’s government showed little concern as Iraqi Kurds took parts of the city and its environs to push back Islamic State, but it is now urging dialogue between Kurdish leader Massoud Barzani and his Iraqi counterpart Haider al-Abadi to resolve disputes.

Kurdish advances in northern Syria as Islamic State has been pushed back have only strengthened Turkey’s determination to oppose independence for Iraq’s Kurds.

In a speech marking the third anniversary of a notorious Islamic State campaign, the prime minister of the Kurdistan Regional Government, Nechirvan Barzani, said Kurds had “tried every way with Iraq but we have completely lost hope.” The vote “will be a call for freedom from subjugation and slavery,” the Kurdish Rudaw news agency on Thursday reported him as saying.

Other senior Kurdish officials have in the past been more circumspect, arguing that the primary aim of a vote would be to ensure greater self-determination rather than outright independence.

Oil Hopes

Cevik laid much of the blame at Baghdad’s door, accusing successive Iraqi governments of policy mistakes that “first alienated Sunni Arabs and encouraged al-Qaeda and then Islamic State to take over Sunni areas,” and also triggered Kurdish disenchantment.

Denying the Kurds sufficient funding has exacerbated financial and social problems in the enclave, he said. Massoud Barzani has been forced into a corner and now mistakenly sees a declaration of independence as “the golden prescription to get the Kurds out of this mess,” Cevik said.

The Kurds are independently developing oil reserves they say may total 45 billion barrels -- equivalent to almost a third of the deposits in the rest of Iraq, according to BP Plc data.

The U.S. has joined those opposing the plan for a vote in September. Brett McGurk, the U.S. special envoy to the coalition against Islamic State, said last month the ballot could hamper the war against the extremists and destabilize the region. “We’ve made those views very clear,” he said July 13, a week after meeting Iraqi and Kurdish leaders in Baghdad.