Syria has become Turkish prime minister Erdogan’s albatross. It also continues to undermine American-Turkish relations.

After sitting on the fence for two years, President Obama has crossed off military options, and focuses on pushing the various sides to the negotiating table. Erdogan, on the other hand, believes that won’t work and persists that Assad must be destroyed no matter the costs if there is to be peace. Closing this gap will not be easy. Nor is it the only gap in Turkish-American relations.

The costs of the Syrian war and Erdogan’s policies continue to be enormous for Turkey: six hundred thousand refugees and counting, billions of dollars to support them and Syrian resistance elements, increasing sectarian differences in his own country, a trouble-ridden border exploited by jihadists, the apparent emergence of a Kurdish autonomous entity in Syria complicating Turkey’s own Kurdish problem, and the erosion of his favored Muslim Brotherhood parties. Continuing failure in Syria has damaged Erdogan’s decade-long political omnipotence and can affect three important Turkish elections over the next eighteen months and thus his political future.

Washington and Ankara agreed early on that Assad must go, but that’s about as far as it went. In coming out against his once bosom friend and throwing his weight behind the opposition, Erdogan miscalculated both Assad’s staying power and US readiness to intervene. It gradually became clear that Washington had no military strategy to hasten Assad’s exit or any intent to get seriously involved in another Middle Eastern conflict. Calls by Erdogan and Arab allies to actively support the rebels and create no-fly zones or humanitarian corridors fell on deaf ears. Lack of American initiative coupled with Turkey’s sectarian approach to the conflict put the two allies at further loggerheads. Worse, Erdogan’s effort to hasten Assad’s departure as well as prevent a Kurdish autonomous area by supporting radical jihadists angered the United States and justified its determination not to get deeply involved in militarily supporting the resistance. The split could recently be graphically seen in recent attacks in major American newspapers on senior Turkish officials providing support to jihadist groups. The Turkish government now declares it is not supporting such groups, but for now that must be taken with a grain of salt.

The September chemical weapons deal and renewed focus on diplomatic talks hit Erdogan hard. He expected that Assad’s crossing of Obama’s “red line” would lead to a decisive Western action, and he was prepared to hold America’s coat. But Assad’s August chemical attack produced diplomacy, not the expected military intervention or greater military support to opposition forces. The US-Russian agreement virtually assured that Assad would remain in power to implement the deal for at least another six months. While the accord significantly reduced the threat of terrorists getting hold of chemical weapons, it also helped boost the regime by averting direct American military intervention and preserving Assad’s conventional capabilities. Nor, apparently, did Obama consult with Erdogan before making the agreement.

Washington’s U-turn and the renewed focus on diplomacy has left Erdogan even more solitary and with little influence to turn the tide. In public, the Turkish government supports the agreement and the planned talks in Geneva, but they and most everyone else have little faith that diplomacy in present circumstances will accelerate Assad’s departure. Erdogan, of course, remains a skilled politician who can change course if events and politics require—he has recently begun to do so in Iraq and made nice (if meaningless) noises with Iran—but Syria offers enormous difficulty.

Aligning the U.S and Turkish positions on resolving the war will require both partners to review their current policies. Turks may have to accept a political settlement in which the regime will play some role, and Washington will need to recognize that it needs to be more involved militarily to bring both opposition and the government to the table and to make Geneva II a success.

Perhaps the most realistic and quicker way the war might be resolved through negotiations is to narrow the military differences between the regime and the opposition—to make clear to Assad he cannot win the war. Right now he seems bent on quashing the rebellion, even at the cost of starving civilian populations to death. To change that as well as reverse the rise of the radical Salafist and jihadist groups, moderate opposition forces must be seriously improved—a difficult feat given the vast differences in views of the opposition and the problems of managing an increased military-supply program. It will require the US to step up and provide arms and other realistic forms of military help to internal opposition forces, and for Turkey and Arab countries to seriously deny aid to jihadist forces and to make every effort to destroy them or prevent them from entering the country—no easy matter. But increased US involvement could lead Turkey and Gulf states to fall in line and throw their weight behind the moderates.

So far the Obama administration remains very skeptical about going down that road. It perhaps also fears spoiling the nuclear negotiations with Iran. But failing to strengthen the moderate forces, and incentivizing the parties to come to the negotiating table, the prospects for political change remain dim—even with a more serious American military effort.

The chemical-weapons agreement, which shifts the focus to disarmament, does not stop Syria’s continuing demise. The drain of the war on the whole region and beyond and the humanitarian disaster are enormous and frightening. Ending the war a little quicker—an act of great mercy for millions of people—may ultimately be beyond us, but it depends in great part on both the US and Turkey urgently reviewing their policies and stitching together American-Turkish cooperation—now seriously lacking in various dimensions. Clearly much more is at stake in Syria than Turkish-American relations.

Morton Abramowitz, a senior fellow at The Century Foundation, is a former American ambassador to Turkey. Omer Zarpli is a research associate at The Century Foundation.