President Recep Tayyip Erdogan of Turkey is famously ambivalent about the threat of the Islamic State (IS). Last fall, he equated the terrorist organization, which has killed tens of thousands, with the Kurdistan Workers' Party (PKK), which no longer participates in armed rebellion against the Turkish state. "For us, the PKK is the same as ISIL," Erdogan said. "It is wrong to consider them as different from each other." Turkey still does not allow U.S. planes to use Incirlik Air Base in southern Turkey to bomb IS targets, nor does it directly act against the terrorist threat right on its southern border.

Yet IS does not seem to be sitting on the sidelines in Turkey. According to Jane's Intelligence Weekly, a recently leaked memo by Turkey’s national police is sounding an "urgent" alarm about the potential for IS-led or -inspired terrorist attacks within Turkey: 

The report warned about the presence of "sleeper cells" throughout the country—particularly in the cities of Adana, Aksaray, Ankara, Gaziantep, Istanbul, Kilis, Konya, Mersin, and Sanliurfa—comprising around 3,000 people with direct links to the insurgent group... Furthermore, in a press conference last week, Foreign Minister Mevlüt Çavusoglu revealed the government's concerns about the possible return of at least 700 Turkish citizens currently fighting for the Islamic State. 

This is just another datapoint indicating the existential threat IS poses to the Turkish Republic, one that Erdogan attempts to manage at his peril.

The Islamic State is a utopian, expansionist organization seeking to fulfill its destiny in the Muslim world—and Turkey is the closest “western” nation to its borders. Does anyone really believe the group with such a grandiose vision of the future—declaring a Caliphate, demanding all Muslims worldwide submit to its authority—is merely content to just run cities like Raqqa, Tikrit, and Mosul, urban centers with little religious or political pedigree? Surely IS chief Abu Bakr al-Baghdadi and his lieutenants have higher aspirations for the organization. 

“Caliph” Abu Bakr knows well that the last legitimate Caliph, Abdulmecid II, sat in Istanbul as the last Sultan of the crumbling Ottoman Empire. The office of the Caliphate in Istanbul was abolished in 1924 not by an invading army but by the stroke of the secular Turkish state; therefore the triumphant return of IS to Istanbul, like Sultan Mehmed II’s conquest of Constantinople in 1453, is not outside the realm of this group’s ambitions.

More recently, Abu Musab al-Zarqawi, the founder of IS’ predecessor group, Al Qaeda in Iraq, had a keen interest in striking Turkey. In November 2003, Zarqawi’s confederate Luay Sakka masterminded a series of well-executed terror strikes around Istanbul, blowing up banks, synagogues and the British Consulate, killing 57 people, including Britain’s Consul General. Sakka was only caught in August 2005, plotting to bomb a number of cruise ships docked in Antalya, Turkey—and the plan was only foiled after a mishap with the bombmaking equipment set fire to his apartment.  

And IS’ media handler told Vice News last year that Turkey should reconsider its summertime decision restricting the Euphrates river into Syria and Iraq, because if "they don't reconsider it now, we'll reconsider it by liberating Istanbul."

Various sources claim IS has been receiving some degree of Turkish support. The road to joining IS in Syria runs through Turkey, as many Europeans and Middle Easterners there and then sneak across the border. In November, Kurds in the besieged city of Kobani claimed IS was targeting them from grain silos on the Turkish side of the border. One former IS fighter even said the Turkish military facilitated his travel in order to strike Ankara’s other “enemy”: the Kurds. 

Currently there is little support for the Islamic State among the Turkish public, but IS could appeal to Turks more than the PKK could ever hope to achieve. Since the PKK’s philosophy is a mix of Kurdish nationalism and Marxist thought (not really a winning global ideology nowadays), it could never cause regular non-radicalized Kurdish Turks or Turkish nationalists to take up their cause. But violent pro-IS student groups are now emerging in Turkey’s top universities and one can buy IS-themed merchandise at a shop near the airport.

Through last summer, many Turks also made a great deal of money by smuggling oil looted from Iraq, making hundreds if not thousands of regular Turks complicit in putting funds into IS’ accounts. So support for IS among the Turkish public could grow if the right ideological and financial benefits can be exploited by the group and are left unchecked by the government.

The Islamic State is a real threat to Turkey. It's only a matter of time before its black flags cross the southern border with Syria and into the Anatolian heartland. Let's hope Ankara is ready for them when they come.