Turkey on Wednesday launched a major assault in northeast Syria, which was unexpectedly greenlit by President Donald Trump following a phone call with Recep Tayyip Erdogan, the Turkish president, on Sunday night. To an astonished national security establishment in Washington, Trump declared that American forces would not stand in the way of Turkish forces, who want to clear a 32-kilometer corridor inside Syria to establish what Ankara calls a “terrorism-free” safe zone. Erdogan, as he did in an earlier phone call with Trump in December, once again managed to convince his American counterpart that Turkey would take care of the Daesh threat in northern Syria. That December phone call had prompted Trump to declare the withdrawal of American forces in Syria, which similarly shocked American military advisers. It was no coincidence that James Mattis resigned as secretary of defense shortly after this. Military advisers eventually convinced the president to slow the drawdown. Fast forward to this week and senior Pentagon officials were again blindsided and are equally frustrated. Even normally loyal Republican leaders in Congress expressed strong disapproval. They have two main concerns. First, the US withdrawal is a major blow to American credibility and a betrayal of Kurdish allies, who trusted Washington in their fight against Daesh. Second, the main beneficiary of the American exit will be Russia, Iran and the Syrian regime. The main issue poisoning Turkish-American relations is the fact that, while Washington considers Daesh the main terrorist threat, Ankara sees Kurdish forces as its principal enemy. This is why, for Erdogan, the easiest way to convince Trump to make such periodic declarations of an American exit from Syria is to assure him that the Turkish military can handle the danger posed by Daesh. Yet it is clear that the Turkish military sees the People’s Protection Units (YPG), the Kurdish militia force linked with the Kurdistan Workers’ Party (PKK), as the top priority in northern Syria. Daesh, in the eyes of Ankara, is a secondary concern, which, in any case, appears to be subdued after the Kurdish-American victory in Raqqa. Turkey’s primary strategic objective is clear: Stop the emergence of a Kurdish autonomous zone in Syria. Given the highly negative reaction in the American media, national security establishment and Congress, Trump recalibrated his position on Monday with a tweet warning Ankara that, if the Turkish military goes “off limits,” the US would “obliterate” its economy. Given the mercurial and erratic style of policymaking coming from the White House, it remains unclear how far the Turkish military incursion into northeast Syria will be allowed to go. For their part, the Kurdish forces in Syria have declared they will fight back. At this point, the Syrian Kurds have considerable leverage on the ground because they are holding 12,000 Daesh prisoners in several detention facilities, as well as some 58,000 of these prisoners’ family members at the Al-Hol camp in northeast Syria. The Kurds could easily release these prisoners to prove that Turkey has no power to control the terrorist threat. Why then was Erdogan so willing to launch this military operation? The short answer is to distract attention from accumulating problems at home. Over the last 12 months, Erdogan’s domestic problems gained an urgent dimension with the deterioration of the economy. Growing unemployment, high inflation and a loss of consumer confidence cost him municipal elections this summer. His party was defeated in Istanbul and other major cities. Economic recessions always create scapegoats. Today, the majority of Turks believe the 3.6 million Syrian refugees in their country to be an economic liability. So it is not surprising that Erdogan is emphasizing that Turkey needs a safe zone to settle a large portion of these refugees. By doing so, he wants to show his political base that he can “solve” the problem. A simple cost-benefit analysis indicates that a military incursion will have serious downsides for Ankara. Omer Taspinar A simple cost-benefit analysis, however, indicates that the military incursion will have serious downsides for Ankara. For starters, there can be serious economic consequences. There are already a series of military and economic sanctions Congress wants to implement in reaction to Turkey’s purchase of the S-400 missile defense system from Russia. Now, if something goes wrong, all it would take is a couple of angry tweets from Trump for Turkey’s economy to once again unravel, as it did in 2017, when he blamed Erdogan for not releasing an American pastor from Turkish detention. Another fallacy in Turkish strategic calculations is the hope that a safe zone can turn into an area where Syrian refugees can be transplanted. Why would refugees in Turkey agree to go to a war zone, where the Turkish military will be fighting Kurdish forces? In fact, Turkey is likely to find itself in a very difficult position. Consider the following likely scenario: Syrians in Turkey will not leave; relations with Washington will be poisoned; the economic situation will deteriorate as Trump gets angry with Turkey after Syrian Kurds release detained Daesh fighters and their families; Russia and Iran will end up asking the Turkish army to leave Syria; the regime in Damascus will denounce Turkey as an invader; and Turkey may very well be bogged down in a war of attrition with the YPG. It is unclear exactly how Turkish-American relations will unfold in the next few weeks. What is for sure, however, is that Turkey is entering yet another very difficult phase in its relations with Washington.