Watching the fall of the ancient Syrian city of Aleppo has been excruciating. Civilians who survived weeks of intense shelling have reportedly been slaughtered by the forces of the Assad government as they have fled the battle zone, some shot in house-to-house searches. Thousands more are trapped with no food, water or shelter. “This is a message from someone saying farewell and who could face death or arrest at any time,” a medic wrote on a messaging service. The United Nations called the catastrophe a “complete meltdown of humanity.”
The Assad forces are close to retaking Aleppo, the last major city not in government hands. In 2011, President Bashar al-Assad ignored the demands of peaceful protesters and unleashed a terrifying war against his people. More than 400,000 Syrians have been killed while millions more have fled across regional borders and to Europe.
But Mr. Assad could never have prevailed without the support of President Vladimir Putin of Russia and, to a lesser extent, Iran. That is a truth that President-elect Donald Trump, a Putin apologist who is surrounding himself with top aides who are also Kremlin sympathizers, cannot ignore. During the presidential campaign, Mr. Trump praised Mr. Putin for being “a better leader” than President Obama. This would be a good time for him to persuade Mr. Putin to end the slaughter.
Mr. Putin’s bloody actions — the bombing of civilian neighborhoods, the destruction of hospitals, the refusal to allow noncombatants to receive food, fuel and medical supplies — are all in violation of international law. At the United Nations Security Council on Tuesday, Samantha Power, the United States ambassador to the United Nations, said to Mr. Assad, Russia and Iran that they had put a “noose” around Aleppo’s civilians and: “It should shame you. Instead, by all appearances, it is emboldening you.”
At the start of the conflict, when hard-nosed diplomacy in the Security Council might have forced Mr. Assad to make political compromises and avert war, Russia used its veto to shield him from criticism and sanctions. By October 2015, when it looked like Mr. Assad was losing, Russia sent jets and troops and became an active combatant on the government’s behalf against the rebels, including those trained and assisted by the United States and Arab nations. Hezbollah, backed by Iran with arms and money, has also been a vital asset for the Assad regime, reportedly deploying at least 5,000 fighters in Syria. The chaos has let the Islamic State establish a headquarters in Syria and become a major terrorist threat.
After calling on Mr. Assad to “step aside” in 2011, Mr. Obama was never able to make it happen, and it may never have been in his power to make it happen, at least at a cost acceptable to the American people or to Congress, which has refused to authorize military action against the Assad government. Mr. Obama, reluctant to approve direct military intervention, was restrained in supporting the rebels and struggled to mold them into an effective fighting front.
Mr. Obama worked with Russia to remove most of Mr. Assad’s chemical weapons from Syria. But other attempts at cooperation — especially the search for a political deal that would end the civil war and enable a unified focus on fighting ISIS — all failed. There is little doubt that Mr. Putin used diplomacy as a feint to enable Mr. Assad’s military victory.
On Tuesday, Russia and Turkey brokered a cease-fire that was supposed to allow thousands of civilians and fighters to leave Aleppo. Yet on Wednesday, bombing by pro-Assad forces continued against the dwindling number of people left alive in the city. When will it stop? That’s up to Mr. Assad, Mr. Putin and Iran.