The last major ground incursion into northern Iraq by Turkish troops in their fight against Kurdish militants was in February 2008.
But now, with the Kurdistan Workers Party (PKK) staging a comeback in Turkey, having recently launched a series of deadly attacks in Istanbul and in the country's southeast, the prospects of a fresh offensive against Kurdish bases in northern Iraq by Turkey's military is growing.
Turkey's military chief, General Ilker Basbug, said on June 22 that he would not rule out the possibility of a new major cross-border offensive against Kurdish militants in northern Iraq.
Basbug's comments come as pressure mounts on Ankara to rein in violence that has been escalating, once again, in the mainly Kurdish southeast of Turkey and along the border with Iraq.
Already, elite Turkish commando units have rappelled from helicopters to mountain positions along the Iraqi border while infantry in armored personnel carriers have been blocking escape routes used by Kurdish militants.
Also on the Turkish side of the border, government troops have been closing in on bands of militants who have fortified themselves on the slopes of two mountains -- Kupeli and Cirav -- in Simak Province.
The PKK said earlier this month that it was scrapping its year-old unilateral cease-fire and resuming attacks against Turkish forces because of military operations against them.
On June 22, suspected Kurdish rebels detonated a remote-controlled bomb in Istanbul that killed four people on a bus carrying military troops and their families.
That follows an attack during the weekend by Kurdish guerrillas that killed 11 Turkish soldiers -- one of the deadliest confrontations for Turkish forces for years in their three-decade war against the PKK.
Turkish Prime Minister Tayyip Erdogan's remarks during a memorial ceremony on June 20 for the slain Turkish soldiers was vitriolic and suggested more military operations are planned.
"They will dry in their own swamp and they will drown in their own blood," Erdogan said. "We have never fallen into intimidation and we will never fall. We have never given up hope and we never will. We have never surrendered to the spiral of violence and we never will in the future."
Turkish warplanes often have bombed Kurdish rebel hideouts in northern Iraq without any forceful response from Baghdad or the government of the Iraqi Kurdish region.
Turning A Blind Eye?
The prospects of another Turkish ground offensive into northern Iraq highlight what appears to be complicit silence on the part of Iraqi leaders about military incursions that simply would not be tolerated farther south.
Meanwhile, recent military operations by Iranian forces against Kurdish rebels in northern Iraq suggests Iraqi and Kurdistan Regional Government officials may have a similar tacit agreement with Tehran about dealing with Kurdish militants.
Iran's Shi'ite government has had its own confrontations with Iranian minority Sunni Muslim Kurds in western Iran.
To be sure, each country in the region has its own goals regarding the Kurdish question. Turkish officials tell RFE/RL privately that Ankara wants a government in Iraq that is "all inclusive" while Iranians are focused on supporting just a Shi'ite government in Iraq.
Nevertheless, what emerges is a scenario suggesting that Baghdad and Kurdish Iraqi officials may be willing to turn a blind eye to national sovereignty concerns as long as incursions by its neighbors are targeting a common foe.
"This all goes back a long way. Back in the 1980s, when Saddam Hussein ruled in Baghdad, there were also understandings and hot-pursuit agreements by which Turkey was able to deal with its insurgency problem by attacking bases of the Kurdish insurgents in Iraq," said Hugh Pope, director of the Turkish Project of the nongovernmental International Crisis Group. "Sometimes it does it in collaboration with Iran, historically. Sometimes it has accused Iran of helping them. Currently, it seems to be in a more cooperative mood with Iran on this particular Kurdish urgent issue."
Baghdad and Iraq's Kurdish regional officials refuse to comment on the existence of such agreements with Turkey or Iran.
But the current president of the Iraqi Kurdish region, Masud Barzani, visited Ankara on June 2 to discuss what authorities described as "security issues." In Ankara, Barzani met with Turkish Prime Minister Erdogan, President Abdullah Gul, and Foreign Minister Ahmet Davutoglu.
Agreements to allow "hot pursuit" incursions would be secret deals rather than overt treaties that are debated publicly by elected lawmakers, Pope said.
"Any agreements on these questions [involving Kurdish militants] are usually secret and between the intelligence and militaries of the countries involved," Pope said. "There was a period of explicit Syria-Iranian-Turkish collaboration on what to do about the Kurdish question. I haven't seen that explicitly followed up in recent years. So I think anything that is going on is done very secretly between the armed forces and intelligence agencies of the countries involved."
Pope said such secret agreements usually are limited in scope and time.
"These alliances come and go, but the one thing I think you will find is constant in the approach of regional states to the Kurdish question is that they will tend to prefer to act to suppress insurgent movements," he said. "There are times, of course, where some states have backed Kurdish insurgents against each other. But I think that is not the case at the moment."
The PKK was founded in the late 1970s as a separatist organization fighting for Kurdish independence in southeastern Turkey. More than 40,000 people have been killed in that struggle -- an overwhelming majority of them Kurds.
The group is listed as a terrorist organization by the United States, the United Nations, NATO and the European Union.
That provides a legal loophole under international law for so-called "hot pursuit" agreements in which countries allow cross-border police or military operations in order to chase down fleeing criminals, militants, or terrorists.