The mobilizing military forces have yet to begin the large-scale incursion into northern Iraq to hunt Kurdish guerrillas that Turkey is threatening.
But reports of limited "hot pursuit" across the border Wednesday illustrate the knife-edge tension in the wake of a string of lethal attacks in Turkey blamed on Kurdistan Workers' Party (PKK) separatists based in northern Iraq.
Analysts say news of the raid is a warning to both the US and Iraqi Kurds, nominally in control in northern Iraq, to clamp down on the PKK, which has waged a fight for a homeland in southeast Turkey since 1984.
The latest violence comes in the run-up to elections next month and are causing Turkey's Islamic-leaning ruling party and the secular military, often at odds, to weigh popular will for an attack against strategic drawbacks.
"We are not there to penalize the people of Iraq," says Seyfi Tashan, director of the Turkish Foreign Policy Institute at Bilkent University in Ankara, the capital. "But we can't tolerate the PKK receiving assistance to kill Turks." On Wednesday, the military announced a "temporary security zone" across three provinces near the Iraqi border where they will limit land and air travel until Sept. 9.
Chief of Staff Gen. Yasar Buyukanit has said that "political" decisions are needed before expanding to "targets" beyond the PKK and going after Iraqi Kurds led by Massoud Barzani, a US ally, whom Ankara accuses of harboring rebels.
"A parliamentary decision is required," Prime Minister Recep Tayyip Erdogan told Kanal 24 television late on Wednesday. "If we are to take a cross-border step, we'll negotiate this with our security forces, and when such a thing is necessary, we'll take it to parliament."
Turkey recognizes "it would be a high-cost exercise for little concrete result," says a senior Western diplomat in Ankara. "They found good reasons not to do this the last 4-1/2 years. [But] if violence gets very bad, then the cost-benefit analysis will begin to change."
That calculation may be shifting already, as Turks this week buried seven paramilitary policemen killed in a PKK attack on a local police station. That strike follows a suicide bombing in Ankara on May 22 – attributed by Turkish officials to the PKK – that killed seven civilians and is reported to have targeted General Buyukanit's convoy as it passed.
Another bomb that week in Turkey's southeast, where ethnic Kurds are the majority, killed six troops. The result has sparked fierce debate about how to respond.
"If you don't dry out this swamp, then this swamp will continue to produce mosquitoes to infiltrate," says Metehan Demir, the Ankara bureau chief of Turkey's Sabah newspaper and a military specialist. "The Americans are not doing this deliberately. But the Americans are not acting as much as they can [to control the PKK in northern Iraq], according to Turkey."
The result, says Mr. Demir, is growing anti-US feeling. "When any Turkish soldier dies, immediate focus [lands] on the US – this is the public view, that the US is not acting sincerely for Turkey as an ally."
In recent weeks, the Turkish military has deployed thousands more troops and 100 tanks along the border with Iraq, ostensibly for exercises that have been billed as a routine reinforcement for an expected spring PKK offensive.
But this buildup is causing speculation that Turkey could repeat past incursions, such as a 1995 operation that lasted for months and a 1997 attack that brought 50,000 Turkish troops deep into Iraqi territory.
Along the rugged border areas, Turkey frequently mounts small-scale operations along the unmarked line into northern Iraq and on Sunday shelled PKK bases at Harkuk, nine miles inside the border.
"They continue to fight Kurdish terrorists that have targeted a number of their citizens in their country," US Brig. Gen. Perry Wiggins said at the Pentagon on Wednesday. "They are conducting aggressive operation in southeast Turkey – counterinsurgency operations –and they continue to do so."
Turkish officials have been boosting rhetoric as the death toll climbs. "The PKK must be eliminated as a problem between Iraq and Turkey," Oguz Celikkol, Ankara's special envoy to Iraq, said last week after a visit to Baghdad. "All the explosives used by the PKK in Turkey are traced back to Iraq."
Still, the recent rise in casualties from PKK attacks – from a low of just 40 to 60 per year since 1999 to some 200 in 2005 and more than 600 in 2006 – has increased pressure on Ankara to act. Some argue that Iraqi Kurds, specifically Mr. Barzani, leader of northern Iraq's autonomous Kurdish region, are using the PKK to pressure Turkey.
Hints from Turkey that it might act to prevent Kurds from gaining control of Kirkuk – the oil-rich northern Iraq city that Turkey fears could enable Iraqi Kurds to declare independence – caused Barzani to warn in April about retaliating in Turkey's Kurdish southeast: "Turkey is not allowed to intervene in the Kirkuk issues, and, if it does, we will interfere in Diyarbakir's issues and other cities in Turkey."
"It's foolish [for Iraqi Kurds] to play the PKK card," says the Western diplomat. "Whatever the final shape of northern Iraq, those people are not going to be able to rely on Iran or the Shiite government in Baghdad. Export and import routes, for oil and goods, is through Turkey."
And the risks are high for Turkey, also. "If you do not prepare the ground politically, it's of no use," says Mr. Demir of Sabah. The choice is stark if the military deploys: go with "tens of thousands of troops and stay and wipe them out," and perhaps clashing with Iraqi Kurdish or even US forces – or go in briefly. But "if you go for one day and leave, and there is another PKK attack – are you going to go back?"
The premier last week said "our patience has run out." But parliament is currently in recess until the vote.
The situation on the ground today is far different from the southeast Turkey of a decade ago, when a marginalized region was subject to a state of emergency, serious human rights abuses, and iron-fist tactics by the Turkish military that destroyed 3,000 villages and displaced tens of thousands of people.
The conflict with the PKK has taken an estimated 30,000 lives, but since the 1999 capture of its leader, Abdullah Ocalan, Turkey's ethnic Kurds have been granted an increasing number of ethnic rights – long denied them by a state that considered them "mountain Turks" – such as speaking Kurdish and running local government.