President Trump celebrated on Twitter this weekend as U.S.-backed forces captured the city of Raqqa, Syria from ISIS. But is the rejoicing premature?

“This notion that you can go and just flatten Raqqa and call it a victory and walk away, as the president is doing, is a huge mistake and a misunderstanding of the complexity,” said news analyst Charlie Sennott on Boston Public Radio today.

Raqqa had been the capital of ISIS' self-described caliphate for three years.

ISIS also lost control of another major stronghold, Mosul, in July.

Despite the victories, Sennott explained ISIS as “an idea” will not be easy to squash, referencing elements of ISIS in Somalia and Afghanistan.

“This idea of ISIS isn't going away anytime soon and it’s going to continue to metastasize all over the world in places like Niger,” he said. “ISIS is an idea — a terribly dark and medieval idea, but it’s an idea.”

Sennott said the capture of Raqqa was a part of a “continuum” of policy that was months in the making.

“It began under Obama; it was finally executed under this administration, but it took a terrible toll on the civilian population there,” said Sennott.

American airstrikes killed more than a thousand civilians, and more than 250,000 people have been displaced by the the fighting.

Sennott admitted Raqqa’s capture is “an accomplishment,” but cautioned against declaring victory too soon. ISIS has used propaganda about American military force as a recruiting tool in the past.

“When you do it with the kind of brutal devastation that they put forward in this community, it’s going to hurt you in the wider scheme of things,” he said.

Charlie Sennott is a news analyst here at WGBH, where he also heads up the GroundTruth Project. To hear his interview in its entirety, click on the audio player above