The defeat of the Islamic State in Iraq and Syria rapidly accelerated during President Trump’s first year in office, beginning with the fall of East Mosul on Jan. 25, and continuing with a cascading series of defeats for the brutal terrorist group over the next 11 months.

The campaign liberated twice as many people and 18 percent more territory as in the previous 28 months under President Barack Obama, according to Defense Department figures.

On Jan. 20 — the day Trump was inaugurated — an estimated 35,000 ISIS fighters held approximately 17,500 square miles of territory in both Iraq and Syria.

As of Dec. 21, the U.S. military estimates the remaining 1,000 or so fighters occupy roughly 1,900 squares miles of mostly barren desert primarily in Syria, where few people live, and where they will be forced to surrender or die.

Between September 2014 when the counter-ISIS campaign began, and January 2017, U.S.-backed forces in Iraq and Syria liberated 13,200 square miles of territory and 2.4 million people from Islamic State rule.

In the 11 months since Trump took office, an additional 15,570 square miles have been reclaimed and 5.3 million people have been liberated.

ISIS areas of influence as of May 2017. (Map courtesy of the Global Coalition Against Daesh)
ISIS areas of influence as of December 2017.

The tipping point in the more than three-year war was the defeat of ISIS in its self-proclaimed capital in the northern Iraqi city of Mosul, which followed eight months of what the top U.S. commander called “the most significant urban combat to take place since World War II.”

When the western part of the city fell in June, thousands of civilians had died, but Iraqi forces prevailed and the will of ISIS had been broken.

“It just snowballed, and it turned into where we are right now, with a full liberation of Iraq, and in Syria, continuing to chase down ISIS elements, the remnants of ISIS elements, in Syria,” said Col. Ryan Dillon, the chief U.S. spokesman for the U.S. led coalition, known as Operation Inherent Resolve.

The liberation of Mosul was followed quickly with victories in Tal Afar, Hawija, and Al Qaim in Iraq in late summer and fall, and then a crushing blow as the Islamic State’s other capital, Raqqa, fell to U.S.-backed Syrian fighters.

It’s not unusual for the most dramatic battlefield gains to come at the end of a conflict when the enemy has been routed, and cities fall like dominos.

And while the destruction of the ISIS caliphate was a validation of the Obama strategy of working “by, with, and through” partner forces, U.S. commanders gave Trump and Defense Secretary Jim Mattis credit for ending what was largely perceived as micromanagement and overly restrictive rules of engagement under Obama.

“We don't get second-guessed a lot. Our judgment here on the battlefield in the forward areas is trusted. And we don't get 20 questions with every action that happens on the battlefield and every action that we take,” said Lt. Gen. Stephen Townsend when he turned over command of the coalition in September.

“Commanders now don't, aren't constantly calling back to higher headquarters asking for permission,” he said. “They're free to act.”

White House special envoy Brett McGurk, who also served in the same post under Obama, agrees the Trump adjustments accelerated the pace of defeat.

“These delegations of tactical authorities from the president has really made a difference on the ground,” McGurk said in August, “I've seen that with my own eyes.”

Critics of the shifted strategy point out that looser rules of engagement bring higher levels of civilian casualties.

As of Nov. 30, the U.S. says 801 civilians were killed by coalition strikes since August 2014, and 695 reports are still under review.

The analysis released by U.S. Central Command concluded that of 56,976 separate engagements between August 2014 and October 2017, the percent of strikes that resulted in a credible report of civilian casualties was 0.35 percent.

Press investigations and outside groups put the tally of civilian casualties much higher, and say the casualty rate has drastically increased since Trump changed the rules. A New York Times investigation has shown the air war has been less precise under Trump. An investigation by the Associated Press said the nine-month battle for Mosul claimed 9,000 to 11,000 innocent civilians, and said the coalition, Iraqi forces and ISIS all share in the blame.

Yet military officials take great pains to point out how accurate their targeting systems are, and say ISIS is responsible for the bulk of civilian deaths.

“I say this with full conviction: The responsibility for civilian casualties in Iraq and Syria lies with ISIS, who have brought misery and death to this region,” Townsend said.

As the year closes out, ISIS has lost 98 percent of the territory it once held across Iraq and Syria, more than 40,000 square miles. “And they have not regained a single meter of those territories,” said Dillon, the chief military spokesman in Iraq.

But don't expect a "Mission Accomplished" banner like the one that infamously served as President George W. Bush's backdrop on the aircraft carrier Abraham Lincoln after the Iraq invasion in 2003. The Pentagon is well aware that the diminished number of ISIS fighters in the Middle East is still a threat, and can still use online propaganda tools to inspire lone-wolf attacks in the U.S., Europe and elsewhere.

"So right now, clearly ISIS is getting broken," Mattis told reporters on Dec. 15. "I think there's still problems, the fight is not over with them, don't believe it when somebody says that ISIS is completely down. We're continuing to fight them, they're on the run, they can't hold against our alliance at all."

Editor's note: The previous version of this story overstated the amount of territory liberated from the Islamic State under President Trump due to an inadvertent math error by the Washington Examiner, not the Defense Department. The number incorrectly reported — 26,800 square miles liberated under Trump — has been corrected to say 15,570 square miles.