“They make a desert and call it peace,” wrote the Roman historian Tacitus, quoting an enemy of Rome about its brutal conquests. The same could be said today of Bashar Assad and his ally Russian President Vladimir Putin in Syria.

At this moment, Syrian and Russian forces, together with Iranian and Hezbollah militia fighters, are preparing to finish their siege of Aleppo. The 275,000 people who reportedly remain in the city are being told to flee. Thousands will do so, choosing to become refugees. The poor souls who remain in Aleppo will suffer a surge in relentless, indiscriminate bombing. And when Mr. Assad, Mr. Putin and their allies have slaughtered all that stand in their way, they will proclaim peace in the bloody sands of the Syrian desert.

The collapse of the most recent cessation of hostilities is not surprising. It failed, as did the Obama administration’s previous efforts to work with Russia in Syria, because as former Secretary of State George Shultz once said, “diplomacy not backed by strength will always be ineffectual at best, dangerous at worst.”

America’s intrepid secretary of state has now taken the meaningless step of suspending talks with Russia over Syria. Meanwhile, Mr. Assad and Mr. Putin are creating military facts on the ground in Syria that will enable them to dictate the terms of a peace secured by carnage. They have decimated coalition-backed Syrian groups, slaughtered countless civilians, consolidated the Syrian regime’s hold on power, and even struck a United Nations humanitarian-aid convoy. And they have done all of this with no consequences. Thus the war grinds on.

While the U.S.-led coalition is making progress in the fight against Islamic State, we cannot forget this terrorist organization is a symptom of the Syrian civil war. The future of that conflict will have significant strategic impact on U.S. national security.