Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin have reached an agreement on Turkey’s controversial military operation against the Kurds in Syria, Russia’s foreign minister, Sergey Lavrov, announced on Tuesday.

The deal helps Turkey to solidify its presence in a large region of Syria and commits the two countries to removing and disarming fighters there who are loyal to the dominant Kurdish military force, known as the YPG, according to a memorandum shared with reporters. By the middle of next week, Russia and Turkey are planning to run joint patrols in a large portion of the Turkey-Syria border region that was previously dominated by the YPG.

The agreement is the latest consequence of President Donald Trump’s decision earlier this month to effectively greenlight a Turkish offensive against the YPG ― and it’s the latest evidence his approach will lead to big losses for the Kurds and their local Syrian partners, who for years worked with the U.S. against the Islamic State group, and to significantly less U.S. influence in the Middle East. The idea of joint Turkish-Russian patrols is especially striking as prior to Trump’s reshaping of U.S. policy, American officials had suggested joint U.S.-Turkish patrols to both manage Ankara’s concerns about the YPG and protect America’s relationship with Turkey, a NATO ally.

While the Kurds are not a party to the deal, Moscow has maintained communication channels with their leadership for years. It’s likely that Putin will now pressure them to comply with the bargain as the best they can hope for, given that they no longer have American backing, and point to the agreement’s promised protection for the Kurds’ largest city, Qamishli.

That suggests a bleak future for Syria’s Kurds. Tens of thousands have already fled their homes out of fear of the Turkish military and the Syrian Arab forces working with the Turks. Tuesday’s deal says that many of the areas the Kurds have left will be resettled by Syrian refugees whom Erdogan wants to remove from Turkey.

Key decisions about Syria and the future of the more than 2 million people living in the once-Kurdish-administered region are now being made by Putin and Erdogan as well as Syrian dictator Bashar Assad. None has much incentive to preserve the level of autonomy that the Kurds and the Arabs, Assyrians and others living alongside them have had for years. In that time, the Kurds developed a form of democratic governance emphasizing gender equality and environmentalism that’s a far cry from the autocratic societies administered by Moscow, Ankara and Damascus.

Two of Trump’s own top officials ― Defense Secretary Mark Esper and Syria envoy James Jeffrey ― have acknowledged that Turkish-backed forces have likely already committed war crimes against the Kurds.

Trump has repeatedly said the U.S. has no responsibility to protect the Kurds, calling them “no angels” last week. He has echoed Erdogan’s claims about the YPG being dangerous because of its ties to the PKK, a transnational Kurdish militant group that fights the Turkish state. Trump also said his move to withdraw U.S. soldiers from the region and allow the Turks to move in was appropriate because he wanted American soldiers to come home. (Those troops have actually been redeployed to Iraq.)

Congressional lawmakers, including Republicans, have repeatedly condemned Trump’s approach to the situation, last week passing a bipartisan rebuke in the House of Representatives and unveiling proposals for new sanctions on Turkey in both chambers of Congress. Tuesday’s news sparked fresh outrage.

“This agreement locks in Erdogan’s land grab in Syria and opens the door for further violence against the Syrian people,” said Sen. Chris Murphy (D-Conn.). Trump’s choices, Murphy said, “have made Putin the kingmaker in determining the future of Syria. Trump’s decision to sell out the Kurds has handed a gift to Russia, Assad, ISIS, and Turkey all at once, and this agreement is proof.”

The president has responded to the public outrage over his abandonment of the Kurds by touting his own dealmaking abilities, imposing limited penalties on Turkey over its invasion and urging Erdogan to negotiate with the U.S. A trip to Turkey by Vice President Mike Pence and Secretary of State Mike Pompeo last week produced a limited promise from Ankara to halt its advance into Syria. But Erdogan secured big concessions, including American pledges to respect his claims to a safe zone inside Syria and to disarm the YPG. Meanwhile, some fighting, including reported Turkish use of chemical weapons, has continued.

The timeline that Erdogan, Pence and Pompeo agreed to expired on Tuesday afternoon, but just hours before Russia announced its deal, U.S. officials indicated they expected the terms of the U.S.-Turkey agreement to continue and Washington to give Turkey some sanctions relief.

The U.S. now appears to be in the bizarre position of working with Putin and Erdogan to weaken a former partner without any guarantee of what America gets in return. Trump has spoken vaguely of defending Syrian oil, but the 200 or so U.S. soldiers left in Syria have almost no partners with whom to do that, while Russia, Assad’s regime and their ally Iran hold strong positions.

Disputes over Syria are likely to become even a bigger headache for Trump. There’s “still a strong appetite for sanctions” on Capitol Hill, a Democratic congressional aide told HuffPost. And one of the Trump administration’s favorite arguments against punishment for Turkey ― that moves like passing sanctions would drive it into Russia’s arms ― took a major blow Tuesday with Ankara showing it’s already willing to treat Putin as a key partner on matters like Syria.

Officials at the White House, the State Department and the Defense Department did not immediately respond to requests for comment.