Only the two at the top can sort this out

NATO allies Turkey and the US are engaged on a collision course that will have a greater effect on the innocent citizens of the two countries than on those who are responsible for the dispute.
Last week the US Embassy in Ankara suspended all non-immigrant visa services at US diplomatic missions in Turkey. It followed the arrest of a local employee of the US consulate in Istanbul on charges of “spying and attempts to overthrow the constitutional order and Turkey’s government.” 
Turkey lost no time in retaliating. In fact, it went one step farther. While the US suspension was confined to consular missions in Turkey, Ankara suspended visas for US citizens in all Turkey’s diplomatic and consular missions. 
The arrest of a local employee can hardly be the real motive for the suspension of visas for 80 million people in Turkey. It is the straw that broke the camel’s back.
Over the years, reasons have accumulated for the US to be unhappy with Turkey’s policies. It began with the Turkish parliament’s refusal in 2003 to allow US troops to cross Turkish territory to invade Iraq, and continued with diverging policies on Syria and Iraq; the arrest of an evangelical pastor who is a US citizen; the decision to purchase S-400 missiles from Russia; and Ankara’s close cooperation with Iran. 
Turkey was also unhappy with the US attitude on several issues. One of them is the strong support provided by the US to the Syrian Kurdish political party, the Democratic Union Party (PYD) and its military branch, the People’s Protection Units (YPG). Turkey considers this party an extension of the outlawed Kurdistan Workers’ Party (PKK), which it has been fighting for decades. 
The US provided 3,500 trailer-loads of equipment and ammunition to the YPG. Turkey sees this as a serious threat to its security, because it could be used by the YPG to help establish an autonomous region in the north of Syria.
The US remained unmoved by Turkey’s demand to extradite the self-exiled Turkish cleric Fethullah Gulen, who lives in the US. Turkey is unhappy with the arrest in the US of a Turkish-Iranian citizen, Reza Zarrab, on charges of conspiring to evade US sanctions against Iran, money laundering and bank fraud. Another Turk, Mehmet Hakan Atilla, Deputy Director of Turkey’s state-owned Halkbank, has also been arrested in the US on charges of conspiring with Zarrab to conduct hundreds of millions of dollars of illegal transaction through US banks on behalf of the Iranian government. More recently, a warrant was issued for the arrest of a former minister of trade in the Erdogan cabinet who is said to have received a $32 million bribe from Zarrab.
Meanwhile the Turkish President Recep Tayyip Erdogan has openly offered to release Andrew Brunson, the Presbyterian minister imprisoned in Izmir for the past year, in exchange for Gulen’s extradition. “You have a pastor, too,” he told US authorities last week. “You give us that one and we’ll work with our judiciary and give back yours.”
Erdogan believes the visa issue is a personal initiative by the departing US Ambassador to Ankara, John Bass. This was denied by the State Department, who said the suspension decision “was taken in coordination with White House” and that Bass had “the full backing of the State Department and was one of the best ambassadors the US ever had.”
Erdogan last week raised the stakes by announcing that Turkish security services will no longer purchase SIG Sauer pistols manufactured in the US. 
The Turkish Foreign Minister Mevlut Cavusoglu talked by telephone to the US Secretary of State Rex Tillerson and they agreed to refer the issue to diplomats. However, the complicated nature of the conflict suggests that it cannot be resolved without the direct involvement of the presidents. Whether the issue will be taken up at the top level is not yet known. 
This exercise looks like it is testing the limits of each other’s determination. The outcome of the row cannot be predicted, but it is not realistic to expect that US will agree to a solution that will show it as a loser. Even if the heightened tension is defused by finding a solution to the visa suspension issue, more profound disagreement between the two countries is likely to continue in other areas.