Iraqi Prime Minister Nouri al-Maliki's government is threatening to sabotage a peace process between Turkey and Kurdish separatist rebels, a plan that could end a 29-year insurgency and transform the region's politics, by refusing to let them into Iraqi Kurdistan.

The first of 1,500-2,000 fighters of the outlawed Kurdistan Workers Party, known by its Kurdish language initials of PKK, reportedly arrived Tuesday in the northern Heror region, which is controlled by Iraq's Kurds, en route to PKK bases in the Qandil Mountains on the border with Iran.

The PKK militants operating inside southeastern Turkey began quitting their hideouts May 8 in line with a cease-fire in March declared by the organization's leader, Abdullah Ocalan, imprisoned in Turkey since 1999 and long branded an arch-terrorist.

That's the first stage in a landmark peace deal with Turkey that was initiated in December 2012 by Prime Minister Recep Tayyip Erdogan, a sharp shift in policy that underlines his ambitions to restore Turkey as a regional power.

"We're at the point of no-return," Turkish Foreign Minister Ahmet Davutoglu observed recently. "The cost of abandoning the process now would be too high for everyone."

Baghdad sees thing differently, mainly that the growing ties between the energy-rich Kurdistan Regional Government to northern neighbor Turkey will intensify the Iraqi Kurds' increasingly independent foreign and energy policy.

Baghdad's relations with Turkey have been steadily deteriorating in recent years.

But despite Maliki's fury at the PKK withdrawal into what his government insists remains Iraqi territory, even if the KRG increasingly acts as thought it's a sovereign power, his options are limited -- unless he takes military action against the KRG.

The Kurds control Iraq's border with Turkey, although it's far from clear whether Ankara would directly support the KRG in a showdown with Baghdad.

KRG and Baghdad forces are locked in an armed confrontation on Kurdistan's southern border in a territorial dispute over the Kirkuk oilfields but Maliki's Shiite-dominated government is preoccupied with an escalating terror campaign by al-Qaida.

The PKK has been fighting for Kurdish rights since 1984 in a conflict in which 40,000 people have been killed.

The withdrawal, which could take six months, is being monitored by Turkey's National Intelligence Organization and the KRG.

The final shape of the peace agreement has yet to be defined but the objective is a permanent disarmament of PKK fighters and some form of autonomy for Turkey's 13 million Kurds, about 18 percent of the population.

Murat Karayilan, the PKK's field commander and de facto leader with Ocalan behind bars, says the success of the plan depends on the willingness of Edrogan's Islamist government to recognize "the existence of the Kurdish people."

There have been other attempts to end the fighting, but all collapsed and despite the PKK cease-fire, there's still deep distrust between the two sides.

Right-wing Turkish nationalists bitterly oppose a process they claim is jeopardizing Turkish unity but the dynamic Erdogan, who's ruled since 2002, is determined to restore Turkish power in a region once ruled by the Ottomans.

Ending the PKK insurrection is an important step toward that goal. It would mark a historic achievement and transform the geopolitical landscape in the region on Iran's western border.

Ankara's growing links with Iraq's Kurds, who were set up in their own self-government enclave by the Americans in 1992 after Saddam Hussein's defeat in the Gulf War, is a vital part of Erdogan's ambitious strategic plan.

He's forged links with the KRG in landlocked Iraqi Kurdistan that include a commitment to build oil and gas pipelines to Turkey's export terminals on the Mediterranean.

That frees the KRG, which sits on oil reserves of 45 billion barrels, from having to use Baghdad's export network and bolsters the aspirations of an independent homeland long cherished by Iraq's 5.5 million Kurds, some 20 percent of the population.

Erdogan's willingness to compromise with Turkey's Kurds and the KRG's acceptance of them, despite Baghdad's opposition, opens up the possibility of an eventual Kurdish entity spanning Kurdish populations in Iraq, Syria, Turkey and possibly even Iran.

Syria's Kurdish zone includes oil fields that linked to the KRG's reserves would provide an economic core for such an independent state for a scattered people that history has treated harshly and left without a homeland.