Turkey-US relations 'entering a risky period'

Turkish President Recep Tayyip Erdogan on Monday lambasted US plans to form a 30,000-strong Kurdish-led border security force in Syria, vowing to "drown this army of terror before it is born." He also warned US troops against intervening should Turkey launch a new operation against the main Syrian Kurdish militia, known as the People's Defense Units, or YPG.

DW: In light of Monday's war of words, do you think that the US and Turkey are on a collision course in Syria? 

Ian Lesser: This is obviously a very serious development and it comes against the background of several years of friction now, specifically over the issue of American support for the YPG and an even longer history of American differences with Turkey over policies towards the Kurds. But the potential for a much more serious political disagreement — even a clash along the border — is there, given the presence of American trainers in the region. Leadership on both sides need to be careful of the language they use, because this can easily inflame an already potentially explosive situation. That sort of language will be read in Washington in ways that are not going to very helpful. By the same token if it is correct that the US has proceeded with this new arrangement without fully consulting Turkey that also is inappropriate and risky.

Read more:The Middle East's complex Kurdish landscape 

Could Ankara's tougher approach, and its military warnings, alter Washington's policy of supporting Kurdish fighters in northern Syria?

Turkey sees this issue through the lens of its own Kurdish issue, its long-running conflict inside the country. There is a great deal of sensitivity, with Turkey seeing this situation in terms of its own interest across the border. The US has long taken a broader view in terms of the struggle against "Islamic State" (IS) in the region. And this latest move is not surprising given the degree of confidence the American military in particular has had in working with Kurdish militia in Syria. The US is very reluctant to give up this security partnership even though Washington obviously is very well aware of Ankara's objections.

The Kurdish Workers' Party, PKK , has long been listed as a terrorist organization by the US administration. And the PKK's ties with the PYD and YPG Kurdish militia groups in Syria are well-known. Isn't that a contradiction, a dilemma? 

The US is willing to overlook the political, logistic connection between the PKK and PYD and the YPG, in the interest of the struggle against IS in Syria. Turkey is not inclined to make this distinction. It is a very difficult circle to square. The US of course, as a NATO ally, remains committed to Turkish security but for Turkey of course this is the number one security issue. It would be easier to manage this problem if the overall relationship between Turkey and the US were on a better footing, but it's not.

Read more: Who are the Kurds?

What would be the US reaction if Turkey would unilaterally launch a military operation in Afrin in northern Syria?

I would simply caution both sides frankly against a policy that is essentially unilateral and assumes that somehow national interest can be pursued without reference to anything else. It's doubly difficult for Turkey because Turkey's policies across the border have echoes inside Turkey itself. 

DW: How can Turkey and the US de-escalate these tensions and address their differences?

These kind of very serious differences between Turkey and the US on security policies are nothing new. We have been close allies but we also had major differences in the past when it comes to policy in detail. It is a very difficult relationship to manage and both countries have been very sensitive to security issues. This makes the situation even more difficult. In terms of managing it, I think it can be managed at two levels but neither is operating well at the moment. The first would be if Presidents Erdogan and Trump saw eye to eye and were able to have a constructive dialogue. That apparently is not the case. The second possibility is that senior military officers like chief of staff, local and regional commanders manage the situation. There have been many discussions of this kind in recent months but they seem not to have produced a convergence on policy. It's not inconceivable that there will be some diplomatic breakthrough in the military to military dialogue — it is quite possible there is every incentive for that. But the more likely scenario is simply for an extremely uneasy and precarious standoff across the border. 

German Defense Minister Ursula von der Leyen praised Jordan as an "anchor of stability" in a violence-ridden region during her recent visit to this country, which now hosts around 300 German soldiers as part of an anti-IS mission. In the past NATO allies have praised Turkey as a source of stability and security in the region. But in recent months, we have heard more and more criticism towards Ankara. Do you think that the perception about Turkey has changed in the West?

Both in the German and American cases there was, for sometime, unease about the vigor with which Turkey was pursuing a strategy against IS. I don't say that Turkey was in any way supporting the movement but I do think there has been growing disenchantment in key ally capitals about the reliability of Turkey as a security partner in the region. No doubt both for Germany and the US there has been a tendency to look to other regional actors.

Do you think that growing tensions between the US and Turkey could give serious damage to the decades-long defense ties and cooperation between the two NATO allies? Do you expect steps like Turkey closing the strategically important Incirlik airbase to the US military?

The US does operate and conduct offensive air operations from İncirlik airbase even with this very strange relationship between Ankara and Washington at the moment. In the past few decades, even going back to the Clinton administration, the Turkish government has been very reluctant to let the US use the base for offensive air operations. Ironically, we are doing this today.

Read more: What is Turkey's Incirlik air base?

This question of uncertainty of access to the base — that Turkey could presumably close down American access — I don't say that's likely but the potential is there. And if the political dispute over policy in Syria intensifies that risk will grow.

Ian Lesser is the Vice President for Foreign Policy at The German Marshall Fund of the United States (GMF).