The Middle East continues its slide into chaos with Turkish warplanes joining the fray in Syria, further embroiling Nato's eastern rampart in that country's civil war, potentially escalating an already punishing conflict.

The airstrikes in Aleppo, coupled with sweeping arrests of Isis (Islamic State) supporters and operatives across Turkey in the past month, appear to represent an end to Turkish collusion with the extremists and raise the prospect of deeper Turkish co-operation with the US-led coalition taking the fight to Isis in the past year.

Since February, an alliance of Kurdish fighters and Free Syrian Army units - the latter believed to be supported by Turkey's National Intelligence Organisation, under US pressure - has driven Isis off a vast stretch of the Turkey-Syria border.

That sweep, bolstered by US airstrikes, reached its limits near the Isis-controlled frontier town of Jarablus just over a month ago, culminating in the fall of Tal Abyad, a frontier town of significant strategic value to the extremist group.

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Demographics and lingering ethnic hostilities forbid the predominantly Kurdish force, known as the People's Protection Units, or YPG, expanding much further west into turf controlled by Arab militias - backed by a host of regional powers, including Turkey - fighting the Syrian regime. It is unclear what concessions Ankara has extracted from the US in exchange for supporting the push to rid border zones of Isis. However, the Turkish press is rife with reports of an "anti-Isis no-fly zone" being established 40km deep and 100km wide in the northern Aleppo countryside, running west from the expanded Kurdish enclave.

Turkey's military reinforced that 100km stretch of border, controlled by Isis on the Syrian side, with tanks, armoured combat vehicles and military personnel this month.

Such a zone - presuming the Kurds can hold the territory wrested from Isis in the northeast - would see the extremist group cut off from the border, which it relies on heavily for foreign fighter flows, resupply and for oil smuggling operations worth millions of dollars each day.

It would also keep supply lines into Aleppo open for rebel factions. Ankara provides robust military and logistical support to a range of rebel factions seeking the overthrow of Syrian President Bashar al-Assad.

However, if indeed established, a limited no-fly zone carries inherent risk: mission creep. Turkish President Recep Tayyip Erdogan has long called for a much broader buffer zone - a costly and high-risk undertaking - to target the Assad regime.

The pugnacious Erdogan and pan-Islamist Turkish Prime Minister Ahmet Davutoglu are likely to be agitating for such a zone with the goal of eventually expanding its remit to provide air support for opposition militias fighting the Syrian regime, notably in northwest Idlib province. The Syrian regime has suffered a string of recent battlefield defeats in Idlib. Turkey, Qatar and Saudi Arabia recently put aside their differences to support a rebel thrust into Idlib led by al-Qaeda's Syria franchise, Jabhat al-Nusra, and the extremist group Ahrar ash-Sham.

An accompanying propaganda campaign, organised out of Doha, has sought to redefine al-Qaeda's Syria faction as a partner to the West and legitimate defender of the Syrian people.

Meanwhile, the ceasefire between Turkey and the Kurdistan Workers' Party, or PKK, has largely broken down, with Turkish planes hammering the group in Iraq where it operates training camps. The PKK, which has waged a three-decade insurgency against the Turkish state, demanding greater rights for the country's Kurds, is closely linked to the Syrian Kurds. Many of its fighters are battling alongside their Syrian brethren in Syria.

Bombarding Kurdish positions probably performs dual functions for Ankara: theoretically pulling hardline nationalist voters to Erdogan's Justice and Development Party, or AKP, in the advent of fresh elections, while extracting concessions from the US in exchange for continued co-operation - the Kurds are essentially America's ground force in Syria.

It is a gambit in which the stakes could not be higher.

Syrian-Turkish relations

Turkey is being dragged further into the four-year conflict in neighbouring Syria.

September 13, 2011: "The Syrian people do not believe [Bashar] al-Assad, I do not either," says Recep Tayyip Erdogan, then Premier, a few months after calling the Syrian leader his "friend". Erdogan warns of civil war in Syria.

October 2, 2011: Syrian opposition leaders announce the creation of the Syrian National Council (SNC), which groups political factions opposed to the Assad regime.

November 15, 2011: Turkey passes its first sanctions against Syria, and halts joint oil exploration with that country.

June 22, 2012: A Turkish plane is shot down by Syrian forces.

May 11, 2013: Twin attacks kill 52 people in Reyhanli, a large Turkish town near the border with Syria.

September 16, 2014: Isis militants attack the Syrian border town of Kobane.

May 16, 2015: Turkey says it has shot down a Syrian helicopter that violated its airspace.

July 20, 2015: At least 32 people die when a suspected Isis suicide bomber attacks a gathering of activists in Suruc.

July 24, 2015: Turkish fighter jets strike Isis positions in Aleppo province.