Some time next week, Donald Trump will likely declare that all of the territory once controlled by the Islamic State of Iraq and Syria has been liberated. He previewed the announcement during a speech Wednesday to the Ministers of the Global Coalition to Defeat ISIS, saying, “It should be formally announced sometime probably next week that we will have 100 percent of the caliphate. But I want to wait for the official word. I don’t want to say too early.”

Back in December, when he announced the withdrawal of U.S. troops from Syria, Trump said that ISIS had been “defeated.” Since then, he has shifted to talking about ISIS’s defeat as a territorial entity. “Caliphate will soon be destroyed,” he declared, when sniping at his own director of national intelligence on Twitter last week. In his State of the Union address, he boasted, “When I took office, ISIS controlled more than 20,000 square miles in Iraq and Syria. Today, we have liberated virtually all of that territory from the grip of these bloodthirsty killers.”

ISIS is indeed on the verge of losing the last sliver of land it controls in eastern Syria, so the emphasis on territory makes sense—because ISIS as an organization is very far from defeated. Pentagon and other estimates suggest it has between 20,000 and 30,000 active fighters in Iraq and Syria, roughly the same as at its peak four years ago, and that’s not counting its affiliates in Libya, Sinai, Yemen, Afghanistan, the Philippines, and elsewhere.

In “liberated” towns in Syria and Iraq, underground ISIS cells are still a threat, the Associated Press reported this week, “carrying out assassinations, setting up flying checkpoints and distributing fliers as they lay the groundwork for an insurgency that could gain strength as U.S. forces withdraw.” Army Gen. Joseph Votel, commander of U.S. Central Command, told Congress on Tuesday, “It is important to understand that even though this territory has been reclaimed, the fight against ISIS and violent extremists is not over and our mission has not changed.”

Trump is right to want to remove U.S. troops from the Middle East, even if there’s plenty of legitimate room for criticism over how he’s doing it. But an honest assessment of the situation would have to concede that jihadi terrorism, and the ideology that inspires it, is not going to be “defeated” by military force. As long as the political conditions that inspire it exist, terrorist groups will fracture and mutate into new forms. And an honest president would concede that the war on terrorism will never have a victory celebration and that there will always be a certain amount of risk.

Trump, however, needs to declare some sort of victory over ISIS so he can take credit for the military strategy pursued over the last two years, claim he fulfilled a campaign promise to “utterly destroy” the group, and justify his desire to remove U.S. troops from Syria—against the advice of many of his own advisers as well as Congress.

And to be clear, the destruction of ISIS as a territorial entity is a major milestone because of the brutality with which the group once ruled over some 10 million people, and because the construction of a literal “caliphate” was a major aspect of the group’s propaganda.

In his eagerness to declare victory, however, Trump is risking the creation of his own “mission accomplished” moment that will come back to haunt him. (Trump has literally used that very loaded phrase with reference to Syria.)

ISIS, formerly known as al-Qaida in Iraq, has already been “defeated” and has reconstituted itself once before, and can do it again. Contra Barack Obama’s Republican critics, the last re-emergence of ISIS wasn’t caused only by the removal of U.S. troops from Iraq in 2011—it was largely due to the marginalization of Iraq’s Sunni population by the country’s Shiite-dominated government. Those conditions exist again today, if not more so, as Iraq’s government carries out a bloody campaign of post-ISIS retribution against former ISIS fighters, their families, and Sunni civilians.

With the killing of four U.S. troops in the Syrian city of Manbij last month, the post-territorial ISIS has already demonstrated the threat it still poses. (It was notable that Trump made no mention of this incident in a State of the Union address that was otherwise heavy on themes of military valor and sacrifice.) Americans have always been less concerned about ISIS as a “state” than its capacity to launch and inspire terrorist attacks outside that state. If ISIS follows the trajectory of groups like al-Shabaab, it may now put more of an emphasis on traditional acts of terrorism now that it’s not spending its time collecting taxes and punishing petty theft.

Trump’s claim that ISIS has been defeated will be cited every time the group, or someone acting on its behalf, carries out an attack that makes the news in the U.S. He should know this: When running for president, he attacked Obama after the 2015 Paris attacks for having recently declared ISIS “contained.” What Obama had meant by that ill-considered remark was that ISIS had stop gaining any more territory, that its growth had been contained. The explanation wasn’t any more politically effective than Trump’s claims likely will be when he says he means only that ISIS’s caliphate had been defeated.