The world abetted Assad’s victory in Syria.

For nearly a year, Syrians and Syria watchers have been anticipating Assad’s move on Idlib. With pivotal help from Russia and Iran, he turned the tide of the war and has been steadily reasserting his authority over the vast swathes of territory his regime lost during the early years of the uprising. What Assad plans to do now is kill the remaining opposition, armed or not, along with the millions who were forced from their homes by conflict and ended up in Idlib, the country’s last refuge for anti-Assad Syrians.

At nearly every stage of the conflict, Russia has served as a willing executioner of Assad’s strategy. Judging by its action and its language, Russia is fully on board with the plan. Yet Western diplomats and humanitarians have pled with Vladimir Putin, the president of Russia, to use his supposed influence over Assad to avoid a disaster. “They have the power to ensure civilians are protected from the relentless unlawful attacks that have characterized much of this brutal conflict,” Amnesty International’s Samah Hadid said in a statement. Well-intentioned diplomats and humanitarians like Hadid believe that Putin doesn’t want a pariah client state on his hands, and that Russia will supposedly use its power to force the Syrian regime to agree to a political solution to end its war rather than resorting to further brute force.

If only there were any evidence to support this theory. It’s naive to think that Russia really wants to avoid a humanitarian catastrophe in Syria, or even—as some otherwise hard-headed analysts have argued—that Putin can compel Assad to do anything at all. Instead, the unfolding catastrophe in Idlib will reinforce the most bitter lesson of the conflict in Syria: When the world order no longer restrains crimes against humanity, cynical and violent strongmen like Assad have more leverage than their superpower patrons.

When Putin has urged Assad to restrain himself in Idlib, he has done so with an eye on the future. Russia would like Turkey’s help in rebuilding Syria and reintegrating it with the region. If Assad carries out his final onslaught, Turkey, which shares a long border with the country and hosts more than 3 million Syrian refugees, will face only bad options: invade to stop the bloodshed, open its borders to another million or more refugees, or appear complicit in a major massacre. “An attack on Idlib will result in disaster, massacre, and a very big humanitarian tragedy,” Recep Tayyip Erdoğan, the president of Turkey, said on September 7.

In hopes of staving off a humanitarian disaster in Idlib, the leaders of Turkey, Iran, and Russia issued a joint statement last Friday after a summit meeting in Tehran. It was notable mainly for its vain hopes that a humanitarian disaster—which would be politically costly for Turkey and embarrassing for Russia and Iran—could be avoided. In their communique, the leaders “reaffirmed their conviction that there could be no military solution to the Syrian conflict and that it could only end through a negotiated political process.”