Turkey's new border battle stretches well into Iraq and its future

There is the battle for Mosul, and then there is the battle to be in Mosul.

How they both end will define what Iraq looks like after ISIS, but also how secure Iraq, Turkey and the entire region will be.

The first is a push to destroy ISIS in Iraq, now in its eighth day. Led by Iraqi forces, and now involving Turkish troops, the operation aims to take Mosul back from the terror group.

The second isn't on the front lines, but it's potentially just as explosive.

Turkish President Recep Tayyip Erdogan is adamant his country and its troops should be involved and that Turkey have a say in the future of Iraq. The countries share a 350-kilometre-long border, after all.

But how Erdogan made his demands, and the responses from his counterpart in Iraq, Prime Minister Haider Abadi, are adding a layer of danger and tension to an already complicated situation.

Turkey has a presence in the Iraqi town of Bashiqa. It has been training Iraqi and Kurdish soldiers there since 2015. Iraq says that presence proves Turkey is an occupying force.

It was Abadi's demand that Turkey pull out of Bashiqa that triggered a series of exchanges that sounded more like a street fight than an attempt at diplomacy.

"You are not at my level, anyway . Your ranting and raving from Iraq isn't important for us at all. Know your place [before you talk]," Erdogan said earlier this month.

Abadi tweeted in response: "We are not your enemy and we will liberate our land through the determination of our men."

'We will consider all options'

As Iraq continued to reject Turkey's role in the Mosul operation, Erdogan repeated his point. "Our security is under threat. How can Turkey not enter Mosul?" he asked delegates at a legal conference in Istanbul.

After a visit from U.S. Secretary of Defence Ash Carter, and a Turkish delegation's visit to Iraq, Turkish forces did join the fight this week, dropping bombs on Islamic State in Iraq and Syria (ISIS) targets.

On Tuesday,Turkey's foreign minister,MevlutCavusoglu,went further,saying the country's involvement might not stop atairstrikes.

"If there is a threat directed at Turkey, we will consider all options, including a ground operation," he said.

But the Iraqi government still doesn't recognize Turkey'srole, and so the fight, on both fronts, continues. And so do the deep concerns of a wider regional conflict.

There are nearly 100 years of rivalry boiling in Mosul.

Turkey is still stung by how the region's borders were drawn after the First World War. After its own war of independence, Turkey felt entitled to Mosul and Kirkuk. The British believed otherwise. The borders as they are now weren't officially agreed on until the 1950s.

It would just spread to all over the Middle East and it will not stay in Middle East.- Murat Bilhan, former Turkish ambassador

"Anything that happens in Iraq touches sensitive chords in Turkey," saidformer Turkish ambassador Murat Bilhan. "It's painful."

And though Bilhan calls the back and forth between Erdogan and Abadi "arrogant" and "undiplomatic," he agrees with Ankara that Turkey should have a seat at the table.

"It is difficult to understand for any Turk, including myself, how Turkey could be bypassed without consulting its opinion in security architecture of the region while countries from far beyond are being called in," he said.

After ISIS

The strained relationship between Turkey and Iraq is more than a diplomatic mess.

The population differences at the two country's borders are time bombs in and of themselves. There are deep worries that any further disputes between Iraq and Turkey could fuel a sectarian free-for-all.

Turkey is concerned that Mosul after ISIS will have a completely different population makeup namely, one that is more Shia than Sunni. Turks follow the Sunni branch of Islam. The current Iraqi government is Shia.

And though Turkey is working with Iraqi Kurdish fighters to combat ISIS, it is opposed to other Kurdish groups in the region.

Its biggest enemy is the PKK, the Kurdistan Worker's Party. The group has been classified as a terror organization by Turkey, the EU and the United States. More than 40,000 people have been killed in the PKK-Turkey conflict since the mid-1980s.

Bilhan compares the potential for sectarian battles to a fast-moving cancer.

"It would just spread to all over the Middle East, and it will not stay in Middle East," he warned. "It will just jump to other continents."

Ridding the region of ISIS is just the beginning.

• Brian Stewart: AfterMosulis recaptured, what then?
• Anti-ISIS fight harder afterMosul: Canadian general