It sounded like a close call when the story broke. Little did we know how close it truly was.

On Thursday, the Pentagon disconfirmed reports that a successful ISIS assault on the al-Baghdadi district of Anbar Province culminated in an assault on the al-Asad Airbase. That 25-square mile facility houses 320 U.S. Marines and other American military personnel who are tasked with advising the Iraqi Security Forces in their fight against ISIS.

According to a Navy spokesperson, early reports that indicated the base had been surrounded and under assault were inaccurate. Only “ineffective indirect fire” near that base had been reported, the Navy insisted. Despite the fact that this facility has come under mortar and rocket attacks in the past, this particular assault was not a threat to American servicemen and women.

A CBS News report published on Friday morning indicated, however, that this attack was more threatening and coordinated than the Pentagon initially conceded. No fewer than eight militants and at least three suicide bombers penetrated al-Asad before they were dispatched by ISF troops. According to CBS News, however, American soldiers were deep enough inside the base at the time of the attack that they were in no immediate danger.

The official said coalition forces were at least a mile and a half away from the attack, and at no point were they under direct threat from the militants. Ain al-Asad is one of the largest bases the U.S. military has used in Iraq — roughly the size of the city of Boulder, Colorado, according to a Pentagon spokesman speaking to the Defensenews.com website last year.

According to reports, ISIS has been regularly shelling Ain al-Assad for the past couple days, but there have been no reports of damage from the shelling or the attempted bombing on Friday.

It remained unclear how the militants managed to get past the approximately 12-mile-circumference security fence around the base, which includes watch towers, barbed wire, and a bridged entrance over a river.

That’s disturbing. Over the course of the last several months, ISIS has demonstrated its interest in both attacking this base and in getting at American troops. This latest assault’s incredible success – coming within two miles of American troops – is only going to embolden ISIS forces to continue their efforts to penetrate al-Asad.