Turkey's suspension of flights to Iraqi Kurdistan's Sulaymaniyah province early this month seemingly came out of nowhere. Ankara previously imposed an extended flight ban on Sulaymaniyah in 2018, citing the presence of the Kurdistan Workers' Party (PKK) there. It lifted that ban after the ruling Patriotic Union of Kurdistan (PUK) in Sulaymaniyah cracked down on PKK-affiliated parties in the province.

Why has Turkey chosen now to impose a new flight ban? What has changed since 2018?

On April 3, Turkey suspended all flights in and out of Sulaymaniyah International Airport (SIA) without explanation. Two days later, Turkish Foreign Ministry spokesperson Tanju Bilgic said Ankara made the decision due to "the intensification of PKK terrorist organization's activities in Sulaymaniyah, infiltration by the terrorist organization into the airport and thus threatening of flight safety."

Ceng Sagnic, Chief of Analysis of TAM-C Solutions, told Gercek News that while PKK activities in the PUK-controlled region "remain unchanged," the new PUK leadership under Bafel Talabani "has intensified its involvement in PKK areas and PKK-backed northern Syria over the past year."

Talabani, the PUK president, visited the Syrian Democratic Forces (SDF) command in northeast Syria in December. He also appeared in a video message streamed to Newroz celebrations in the Kurdish-majority city of Diyarbakir in southeast Turkey as part of an event organized by the mainstream Kurdish movement in Turkey.

"These appearances, coupled with the PUK's statement announcing its direct involvement in the so-called 'helicopter incident,' are likely indicators of intensified PKK activity in the PUK zone for Turkey," Sagnic said.

On March 15, two helicopters crashed in Iraqi Kurdistan's Duhok province en route to Sulaymaniyah. Nine SDF members perished in one of the crashes, including a relative of SDF leader Mazloum Abdi, who Turkey considers a terrorist. Questions emerged over who owned the Eurocopter AS350 carrying those SDF troops after the U.S.-led coalition denied any involvement. Turkey clearly saw the incident as proof that the PUK was supporting the SDF through Sulaymaniyah’s airport.

Sagnic argued that, notwithstanding Turkey's perception, intra-PUK disputes likely played a significant role in Bafel Talabani's "recent bold moves" concerning the PKK and PKK-linked groups.

"Bafel feels obliged to seize the pan-Kurdish card marked by support to other Kurdish groups from the expelled former PUK co-chair and his cousin Lahur Talabani," he said. "In that regard, Bafel Talabani might well have provided additional support to groups within the PKK ecosystem, but no significant incidents have occurred to mark an extraordinary PKK activity in this region."

Bilgic alluded to "infiltration by the terrorist organization into the airport" as part of Turkey's justification for the ban. Sagnic has "no doubt" that PKK-aligned groups or groups considered part of the PKK network use SIA "more freely than other airports across Iraq."

"This may also suggest the PKK itself also uses the airport to some extent, especially for international travel," he said. "However, this has been the case for nearly a decade now and is not new information for Turkey."

"That said, coalition flights transporting SDF cadres between the Kurdistan Region and northern Syria, including Erbil, are not new either," he added. "What's new is the revelation that some of these flights were actually operated by SDF (or PKK) members without the coalition's involvement on a route exclusively used by the coalition."

On April 7, a drone strike attributed to Turkey (although officially denied by the Turkish defense ministry) targeted a convoy that included American military personnel in SIA but did not cause casualties or significant damage. Preliminary reports said that Turkey intended to kill Mazloum Abdi in the strike. The SDF initially dismissed such reports but later confirmed, on April 8, that Abdi was in act in Sulaymaniyah on the day of the attack.

More broadly, Sagnic noted that Turkey's ban on flights in and out of SIA does not merely function as a flight ban but also as diplomatic and economic sanctions against the PUK.

"It is an economic sanction since it forces many international airlines to either change their routes or halt flights to and from Sulaymaniyah," he said. "And it is a diplomatic ban that forces the PUK to depend on Erbil or Iranian and Syrian airspace to access the rest of the world," he said.

Turkey has said the flight ban will remain in place for three months, although Ankara could easily extend that if the PUK does not offer concessions.

In September 2017, Iraqi Kurdistan held an independence referendum. Baghdad responded by shutting the airspace to Iraqi Kurdistan's two international airports. Turkey followed its lead, banning all flights in and out of the autonomous region. In March 2018, Turkey lifted its flight ban on Erbil International but not on SIA, citing the PKK presence in the PUK-controlled province. The ban lasted until the end of the year and was only lifted after the PUK closed the offices of a PKK-affiliated party on its territory in a clear move to placate Ankara.

Turkey may leverage the current flight ban, and possibly even drone strikes in Sulaymaniyah, to similarly pressure the PUK into making similar concessions.

"The only viable way for Turkey to lift the ban with the knowledge that PKK and PKK-linked groups will continue to use Sulaymaniyah and its airport is receiving concessions from PUK, similar to the concessions in the past few years, allowing increased Turkish targeted killings in the PUK zone," Sagnic said.

He noted that there have been rumors that some of the intelligence Turkey successfully used for assassination operations against PKK cadres was "provided by PUK as part of the party's efforts to rid itself of Turkish sanctions."

"Similar demands may come from Turkey this time too, especially as Turkish president Erdogan needs propaganda material for the upcoming elections in May."

*Paul Iddon is a freelance journalist who writes primarily about the political and military affairs and history of the Middle East.