During a visit to Baghdad on Monday, Secretary of Defense Ashton Carter announced another 560 U.S. troops would be headed to Iraq to assist with the forthcoming assault on the Islamic State stronghold of Mosul.

Reuters reports that most of these new troops will work from the Qayara air base, which was recaptured from ISIS over the weekend by Iraqi government forces, with U.S. air support. Qayara is about 40 miles from Mosul.

“With these additional U.S. forces I’m describing today, we’ll bring unique capability to the campaign and provide critical support to the Iraqi forces at a key moment in the fight,” Carter said from Baghdad, anticipating that the additional American boots would hit the ground within “days and weeks, not months.”

“We’re going to need airfield operations, and if you want to go in concentric circles around that we’re going to also have a logistics footprint there to facilitate the flow of goods and supplies and personnel through that airfield,” explained Army Lt. Gen. Sean MacFarland, the top U.S. commander in Iraq, as quoted by the Washington Post.

“We’ll have a security envelope around that. We’ll have a communications capability there and a command-and-control or headquarters unit there, as well. There’s nothing really very sexy in any of that, but it’s all very necessary to keep the campaign moving forward,” MacFarland continued.

The Washington Examiner cites Pentagon officials who hope the new American deployment will mark a “tipping point” in the war against ISIS.

Confidence in the Iraqi army was greatly increased by their “surprisingly easy victory” in Qayara. A force of about 50 Iraqi tanks was able to catch the Islamic State’s fighters by surprise after a bold dash up the western side of the Tigris River. It has been described as the largest Iraqi armored operation since Saddam Hussein invaded Kuwait in 1990.

As for the degree of American involvement in the operation, beyond providing air support, the Washington Post reports that some “U.S. advisers based at Camp Speicher” near Tikrit were on hand, and Iraqi commanders are under orders to keep many details of the operation secret.

“Carter, who famously castigated the Iraqi forces a year ago for showing ‘no will to fight’ when Ramadi fell to the Islamic State, was singing their praises in remarks to the U.S. military advisers who have been helping to rebuild an Iraqi Army that was riddled with corruption and plagued by self-doubt last year,” the Examiner writes.

“This is a huge victory for the Iraq forces, and a huge boost to their self-confidence. Last year we were pushing for them to retake Ramadi, and it wasn’t happening. Same thing with Fallujah. But when they won in Fallujah, and it was easier than expected, they began to believe, ‘Hey, we can beat these guys,'” said a Pentagon official.

Hidden behind these upbeat revised assessments is a previously under-reported sense of gloom about the Iraqi military’s ability to retake Mosul, without causing a horrendous civilian bloodbath.

The Qayara base is nicely situated to provide tight U.S. command-and-control over Iraqi forces, while the Kurdish peshmerga hits Mosul from the other side. The Washington Post notes that Qayara is also a large enough airfield to handle large cargo planes, unlike other facilities held by the Iraqis in the area. With some 500 U.S. troops holding the position, it is less likely to be retaken by ISIS during a counterattack, if the Iraqis under-perform, and ISIS fighters are less likely to think recapturing Qayara is a possibility.

The Washington Post notes that when announcing the increase of 560 U.S. troops, Defense Secretary Carter “did not rule out that MacFarland could temporarily base additional forces in Iraq that do not count against troop limits set in the United States – something that gained attention in March as the Marines set up a fire base southeast of Mosul at Makhmour.”

Even then, it only came to the attention of the American public because one of the Marines, Staff Sgt. Louis Cardin, was killed by an ISIS rocket attack.