For the first time since Turkey declared it had launched a military campaign to create an “ISIS-free zone” in Syria following the terror attack in Suruç, Turkey, the Islamic State has initiated a new, alarmingly successful offensive near the Turkish border.

Reuters and Turkish newspaper Hurriyet report that the initiative has begun north of Aleppo, Syria, and has targeted Syrian opposition groups. ISIS has this week captured a border village, Umm Hosh, and killed dozens with four car bombs in the town of Marea, according to the watchdog Syrian Observatory for Human Rights. “The situation in northern Aleppo is bad,” said one rebel fighter, referring to the province of Aleppo in which the Marea and Umm Hosh incidents occurred.

In response to the attack, Pentagon spokesman John Kirby emphasized that the White House believes Turkey is committed to fighting the Islamic State:

Everybody is focused on the ISIL threat inside Syria, and Turkey has itself said that is where the locus of its energy will be applied. We continue to have conversations with them about how best to bolster security in the region and how to achieve a common objective. We’ve also been very clear that we’re not interested in doing anything that’s going to change the territorial integrity of Syria.

Another Pentagon spokesman, Maj. James Brindle, told state-run Turkish outlet Anadolu Agency that the United State has “requested Turkey not to undertake independent counter-ISIL strikes in Syria, to ensure safe air operations for the coalition in dense airspace.” That statement follows an incident reported by Fox News yesterday in which Turkish air force officials gave American troops in Iraq only ten minutes to evacuate before an airstrike, nearly killing several American soldiers and putting in danger members of the Kurdish Iraqi Peshmerga, who were training with the American troops.

That incident has brought to the fore major concerns the international community has raised regarding Turkey’s true intentions in launching this campaign against the Islamic State, particularly among Kurdish populations and their supporters who insist that Turkey is more concerned with eradicating the Kurdistan Workers’ Party (PKK), a group that has a history of military success against ISIS, than ISS itself.

Skeptics note that the fight against the PKK has been more successful than that against ISIS. Turkish airstrikes have killed or wounded nearly 800 PKK fighters so far, and anti-terror sweeps have resulted in the arrests of over 800 of the same within Turkey. The PKK is a Marxist, U.S.-designated terrorist group, but its ideology makes it a sworn enemy of ISIS.

Most recently, 19 more PKK terrorists were arrested this week in Turkey, compared to 12 arrested for suspicion of supporting ISIS.

As a result, many speculate that Turkey, which has categorically opposed the creation of a sovereign Kurdistan near its borders, is using ISIS as an excuse to engage in military action, but doing so mostly against the PKK and the Syrian Kurdish People’s Protection Units (YPG and YPJ). “In Turkey’s recent roundup of 1,300 people it identified as terrorism suspects, 137 of those arrested were linked to the Islamic State and 847 were linked to the P.K.K.,” notes The New York Times, “At the same time, Turkey bombed P.K.K. positions in southeastern Turkey and northern Iraq, claiming that the militants could attack Turkish areas from across the border.”

A columnist for Rudaw, a Kurdish publication, notes that many “believe Ankara’s ultimate goal is to ensure that Kurdish YPG forces are unable to capture the ISIS-controlled town of Jarablus. This is the only town on the border with Turkey in ISIS hands, after it was defeated in Gire Spi in late June by Kurdish fighters.” The columnist concludes that, “a Turkish national security point of view, an ISIS-controlled area that keeps Kurdish-controlled territories separated from each other in Syria makes total sense, at least in the short run,” making it difficult to believe Turkey is working first and foremost to destroy ISIS strongholds.

The suspicion has forced the Turkish government to once again deny any involvement with the Islamic State. “Turkey never, ever supported ISIS or any group linked to ISIS,” said Prime Minister Ahmet Davutoğlu in public statements on Wednesday, “This is very unfair assessment and I categorically reject this.”