In his State of the Union address, President Trump claimed a very clear policy accomplishment: the military defeat of ISIS.

“Last year, I pledged that we would work with our allies to extinguish ISIS from the face of the earth,” the president said. “One year later, I’m proud to report that the coalition to defeat ISIS has liberated very close to 100 percent of the territory just recently held by these killers in Iraq and in Syria.”

There’s real truth here. The amount of territory controlled by ISIS declined by 60 percent between January and October 2017, according to a count by IHS Markit, a strategic intelligence firm. The group lost control over both Mosul, Iraq’s second-largest city, and Raqqa, which served as the de facto capital of ISIS’s so-called caliphate; it now no longer controls a major populated city in either country.

Yet Trump’s comment implies that nearly all of ISIS-held territory was liberated in the past year. This isn’t true. In fact, it’s not clear that Trump deserves much credit for these developments — if any. His counter-ISIS strategy has, for the most part, been a continuation of the one the Obama administration began back in 2014, which had already been steadily chipping away at the group’s territory.

“Whatever successes the Trump administration is claiming against ISIS are actually a product of the Obama administration’s approach,” says Jennifer Cafarella, the senior intelligence planner at the Institute for the Study of War.

To be fair, Trump’s approach wasn’t 100 percent identical to Obama’s. He did relax regulations designed to prevent civilian casualties, which appears to have led to a larger number of strikes on ISIS targets per day. It is certainly possible that this led ISIS to lose territory at a faster rate, but experts say there’s no way to tell for sure — and that the group’s losses would have been inevitable without Trump’s changes.

So while it’s true that ISIS lost a lot of territory under Trump’s watch, there’s little evidence to suggest that he can count it as his accomplishment.

How Trump did and didn’t change the ISIS war

The Obama administration’s strategy for countering ISIS, launched soon after the group seized huge amounts of Iraqi territory in June 2014, mostly slotted the US into a supporting role. The Iraqi military and various armed factions in Syria would take the lead in risky ground combat against ISIS; the US and its allies would provide training, weapons, limited special forces deployments, and airstrikes. The idea was to roll back ISIS’s territorial gains at a limited cost to the US, while building up the capacity of local partners to keep the group down once it was defeated.

On a purely military level, this strategy proved fairly effective. ISIS was outnumbered by its enemies in the region and outgunned by the coalition, and had no way to shoot down American planes. ISIS’s territorial conquests had basically been stopped by the end of 2014; by the time of the 2016 election, it had lost a third of its peak territory.

After Trump took office in January 2017, his administration didn’t change the basic parameters of the strategy — opting not to fix something that wasn’t broken. The overall strategy, to assist and empower local allies rather than win the ground war using large troop deployments, remained intact.

Trump did change how the airpower part of the strategy worked, in two distinct but related ways.

First, he loosened the Obama-era rules of engagement — rules that govern when it’s acceptable to launch an attack — in effect making it easier to launch airstrikes against ISIS targets that might unintentionally kill civilians. Second, he changed the procedure for ordering airstrikes, giving battlefield commanders more discretion to launch airstrikes with permission from people higher up the food chain.

The exact nature of these changes is classified: We don’t know how the Trump administration defines “too much risk” to civilians, or how different its standard is from Obama’s. But data suggests that Trump’s rule changes did have at least some measurable impact on the US air campaign in Iraq and Syria.

The following chart, from the watchdog group Airwars, shows the number of strikes per month by the US-led anti-ISIS coalition. You can see a clear increase in the pace of strikes beginning in early 2017 — right when Trump took over:

During the same time period, you also see a significant spike in reports of civilian casualties caused by coalition strikes:

So while the overall strategy may not have changed, there’s at least some evidence that Trump did change the way the war was being fought.

Did Trump hasten ISIS’s collapse?

Evaluating the broader effects of Trump’s changes to airstrike policy is extremely tricky, mostly because the Obama strategy had already set ISIS on a path to defeat. It wasn’t as if Trump came in and righted a sinking ship; in fact, if he had changed nothing at all about Obama’s policy, ISIS still would have been pushed out of its major cities eventually.

“The Trump administration didn’t screw up the Obama plan, which we were all kind of afraid of,” one former National Security Council official tells me. “They at the very least continued a working policy.”

So the question is less about whether Trump deserves sole or majority credit for ISIS’s collapse, as he clearly does not. It’s more about whether his changes to the rules of engagement hastened ISIS’s territorial collapse. And on that question, experts really aren’t sure.

“It was inevitable that the caliphate would fall,” says Daveed Gartenstein-Ross, a senior fellow at the Foundation for the Defense of Democracies. “It wasn’t inevitable that the caliphate would collapse in a matter of months in the middle of 2017. As far as I know, most analysts were not predicting that to happen.”

Neither Gartenstein-Ross nor any other expert I spoke to would venture a guess as to how much, if at all, Trump’s changes to the rules of engagement caused that rapid collapse.

It’s possible that it did — the timing is certainly suggestive. But it’s also plausible that it made no difference whatsoever: that ISIS had been under pressure for years and eventually cracked all at once.

“It’s not unusual for an armed force to rapidly lose territory once its forward units are defeated or demoralized,” says Robert Farley, a political scientist who studies airpower at the University of Kentucky. “I don’t think you could say conclusively one way or the other that the loosened rules of engagement had an impact.”

So Trump’s claim of credit for ISIS’s defeat isn’t akin to his truly outlandish lies, like his claim that Obama “wiretapped” Trump Tower. It’s possible there’s some grounding in truth, that he really led to ISIS’s control over a large amount of territory disappearing a bit faster.

But the president’s comments during his speech — that “one year” since his inauguration, the coalition had “liberated very close to 100 percent” of ISIS-held territory — is deeply misleading. if you just listened to the speech, you never would have known that it was the Obama administration that put ISIS on the path to defeat, and that Trump only slightly tweaked their framework. You also wouldn’t get a sense that Iraqi and Syrian forces did the brunt of the fighting, and thus deserve the brunt of the credit.

And those fighters, for what it’s worth, seem skeptical of Trump’s claim. When CNN’s Peter Bergen interviewed Gen. Abdul Wahab al-Saadi, the leader of Iraq’s elite Golden Division, the general couldn’t fathom the idea that Trump had affected the war in any way.

“There was no difference,” al-Saadi said, “between the support given by Obama and Trump.”