Even on a normal day, Ibrahim Khalil, the complex straddling Turkey and Kurdish-controlled northern Iraq, is a rather unusual international border crossing. Although it is an entry point into Iraq, there are no Iraqi soldiers, no Iraqi flags, and seemingly no Iraqi federal officials. Instead, the Iraqi side is controlled by the Kurdistan Regional Government, which enforces its own customs and immigration policies, enforced at checkpoints manned by Kurdish peshmerga fighters under the flag of Kurdistan — a red, white, and green tricolor with a golden sun.Viewed from Turkey, these trappings of autonomy are a worrying prelude to an independent Kurdish state, a prospect to which Turkey — with its own restive Kurdish minority — is implacably hostile. Turkish soldiers often harass Kurds crossing at Ibrahim Khalil, according to Iraqi Kurdish border security officials. They confiscate books or documents that use the word "Kurdistan", deny passage to women called Kurdistan — a common female first name — and to Kurds of foreign nationality whose passports list "Kurdistan" as a place of birth.Turkey's latent hostility towards Iraqi Kurdistan has grown more active following last month's killings of about 40 Turks, mostly soldiers, by fighters of the Kurdish Workers Party, or PKK, a militant group of Turkish Kurds at war with the Turkish state (and branded a terrorist organization by the U.S. and EU). Turkey accuses Iraqi Kurdish leaders of allowing the PKK to maintain bases in northern Iraq as part of a greater Kurdish national agenda. (Iraqi Kurds say they are helpless against a hardened guerilla group that Turkey itself has failed to defeat in over 20 years of war — Turkey rejects these claims of helplessness, pointing out that the Iraqi Kurdish authorities have not even acted to cut off supply lines to the guerrilla movement's camps.) Amid rising tension, the Turks have threatened cross-border military action against the PKK, and also to close their side of the Ibrahim Kalil border crossing as punishment.But on a recent road trip through the mountains of northern Iraq along the Turkish border, it was easier to find Turkish soldiers than Kurdish rebels. The Turkish army maintains at least four bases inside northern Iraq as a result of an agreement with Saddam Hussein after the American no-flight zone created a power vacuum in the region during the 1990s. In the town of Barmani, the Turks have a base with 35 tanks, and are repairing a disused air strip and building up troop levels, according to Iraqi Kurdish intelligence officers. But this is no invasion: The Turks supply and man these stations simply by sending uniformed soldiers through the Ibrahim Khalil border on buses.While the Turks drive their tanks through Barmani in broad daylight once a week, the PKK guerillas are more elusive. Although the Turkish army claims that the PKK is using northern Iraq as a staging ground for attacks inside Turkey, the PKK's main bases are in the Qandil mountains, near the border with Iran and beyond the easy reach of a large Turkish force. The few PKK bases near the Turkish border are also difficult to reach, located long distances on single-track dirt roads high in classic insurgency country. One camp that's home to some 300 fighters in a ravine carved by the cold blue waters of the lower Khabour river looked like a beautiful place for an invading army to die. Turkish incursions into northern Iraq are unlikely to have much effect on either PKK fighters hiding there, or on those inside Turkey — where the PKK claims to have twice as many fighters as it does in Iraq.The harsh mountainous terrain and the dispersal of the PKK makes it unlikely that the Turkish army will stage a major invasion this year and risk being caught in the mountains with winter fast approaching. Still, the mere threat of Turkish action has had an effect: The last stable part of Iraq no longer feels quite the safe haven it had become for thousands of refugees from the civil war in the rest of the country. "We fled from Baghdad, and now we are afraid of the Turks," said Mary Toma, a Christian refugee from the Dora neighborhood of Baghdad who has taken shelter with her husband and two teenage daughters in the mountain village of Gededky, within artillery range of Turkey. "Where should I go? What should I do?" she asked.And the showdown has also reminded Kurdish leaders how dependent they remain, despite the trappings of independence, on their patrons in Washington, who are working to diffuse the crisis, and on the government in Baghdad, which leapt to the defense of the Kurdish region. And since many Kurdish observers suspect that Iraqi Kurdish independence — not just the PKK — is the target of Turkey's efforts, the Turks may have already won this skirmish in the battle of northern Iraq.