Then came this clarification: Staying “is not necessarily American boots on the ground,” said James F. Jeffrey, the State Department’s special representative for Syria. What’s more, “we’re not going to force the Iranians out of Syria . . . because force implies force, military action. . . . This is all about political pressure.”

So the good news is, President Trump is not planning to start a war with Iran in Syria without congressional authorization. The bad news is, his administration still lacks a realistic policy for ending the ongoing conflict and the threat that it, and Iran’s presence, pose to vital U.S. interests.

AD

AD

As Mr. Jeffrey pointed out during a briefing with reporters, Iran’s aim in Syria is not just to prop up the regime of President Bashar al-Assad but to entrench its own network of long-range missiles, antiaircraft systems and other arms that would give it “power projection over the region.” More than 200 airstrikes by Israel have failed to stop the Iranian buildup. But U.S. strategy boils down to trying to revive a moribund U.N. peace process that the Assad regime has implacably resisted. The theory is that if a political settlement can be reached that is acceptable to Iran and Russia, the Iranians might be induced to withdraw.

Mr. Jeffrey points out that the scenario envisioned by Russia and the Assad regime for 2018 — that their forces would recapture remaining rebel-held areas, the United States would withdraw from the territory it controls in eastern Syria, and international reconstruction aid would start to roll in — has failed to materialize. He says Mr. Trump, who has pushed in the past for the withdrawal of U.S. forces, is now prepared to leave them there. The United States and Europe have meanwhile joined in refusing to supply rebuilding aid until there is a political settlement.

Russian President Vladi­mir Putin recently held up a major new offensive in the northern province of Idlib, where 3 million civilians are crammed in with a few tens of thousands of rebels and al-Qaeda militants. Instead, he agreed with Turkey on a buffer zone from which the rebels are to be evacuated. That, in theory, could create space for Mr. Jeffrey’s diplomacy. But the United States still lacks meaningful leverage over the Assad regime. It can only hope that other actors — Turkey, Israel and Russia — somehow create conditions for peace and an Iranian withdrawal. Otherwise, the United States is going to be stuck in Syria, unable to control events or to leave, for a long time.