MUNICH — Senior U.S. lawmakers and military officials are pressing America’s allies in Europe to commit hundreds of troops to create a buffer zone on the Syrian side of that country’s border with Turkey as the bulk of U.S. troops there withdraw. If they agree, President Trump is open to keeping some U.S. troops there to help them, according to Sen. Lindsey O. Graham (R-S.C.).

Graham outlined what he called the “post-caliphate strategy” and the U.S. drive to seek European troop deployments in northeastern Syria during public remarks at the Munich Security Conference, an annual confab of officials, lawmakers and journalists from around the word. He told the mostly European audience that he had discussed the plan with Trump extensively — including Friday — and said that, based on these conversations, U.S. lawmakers and officials would be using their bilateral meetings at the conference to ask European allies to pitch in.

“I’m hoping that President Trump will be coming to some of you and asking for your help and you will say yes. And in return, the capability that we have that is unique to the United States will still be in the fight in Syria,” Graham said.

He told the audience that Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff, would also be asking European leaders to contribute troops to northeastern Syria during meetings here in Munich. He said the Islamic State’s physical caliphate is all but gone, except for a few remaining pockets that are being cleaned up now. Graham thanked Trump for intensifying the U.S. campaign against the jihadists.

“All of us have suffered from letting the caliphate be created. Now it is destroyed. What follows?” Graham said. “The post-caliphate strategy should be different than the fight to destroy the caliphate.”

Graham read off a list of European terror attacks that were organized or inspired by the Islamic State and argued that European countries have a vital security interest in ensuring stability in areas of Syria recently liberated from the Islamic State and still outside the control of the Assad regime.

“If we do not have a game plan, Turkey will go into Syria and deal with the YPG threat,” Graham said, referring to the U.S.-supported Syrian Kurdish group that is viewed by Turkey as a terrorist organization. Graham added that the West has a responsibility to protect Kurdish forces that have done the heavy lifting in the fight thus far.

“We need a safe zone to deal with that problem. The troops in that safe zone need to watch for the reemergence of ISIS,” he said. “You can do this with a fraction of the forces that you had in the past.”

Officials told me that the Pentagon is already working on the outline of the safe zone plan, even before any other countries have committed troops. The idea is that European countries would pitch in a total of about 1,500 soldiers. If that happens, Trump would be willing to keep about 200 soldiers in northeastern Syria, to provide support such as intelligence as well as command and control.

There’s no notion that the new mission would be conducted under a NATO flag, but individual countries that are NATO members are being specifically asked to contribute troops, including Britain, France and Germany.

U.S. lawmakers and officials are pitching this idea to European leaders in meetings all weekend. They know it’s going to be a tough sell at a time when the Trump administration is battling European allies on Iran, trade and burden-sharing. They also know that Trump is unpopular in Europe.

But this is the only play the United States has left to maintain some influence and presence in northeastern Syria, and Graham is hoping European leaders will see an opportunity to help mitigate Trump’s planned withdrawal as a way of protecting their own security.

“The president can be a handful,” Graham admitted. “But so can many of you.”