Insurgent fighters wearing U.S. Army uniforms breached the defenses of the main British-run air base in southern Afghanistan on Friday. Firing guns and rockets and apparently triggering suicide vests, the attackers killed two U.S. Marines and damaged or destroyed several hangars and fueling facilities. Before they were all killed or captured, the insurgents also managed to destroy six U.S. Marine Corps jet fighters and "significantly" damage two others, landing a shocking blow against NATO air power in the region.

The attack on Camp Bastion, in restive Helmand province, came after the Taliban vowed to take revenge for the release by a mysterious U.S. filmmaker of an inflammatory – albeit amateurish – movie mocking the Muslim prophet Muhammad. The insurgent group had also threatened to kill or capture the U.K.'s Prince Harry, who recently deployed to Camp Bastion as an Apache helicopter pilot. The prince "was never in any danger," NATO's International Security Assistance Force stated.

The assailants' true motives are impossible to verify, but the attack underscores the Afghan insurgency's boldness and striking power in the waning years of the U.S.-led NATO intervention.

The assault began "shortly after 10:00 p.m." when "approximately 15" insurgents – organized in three teams and wearing American uniforms – "penetrated at one point of the perimeter fence" and "executed a well-coordinated attack against the airfield," according to ISAF. The Harrier jump jets destroyed or damaged in the assault had been parked out in the open on the flightline, the alliance stated.

The Harriers reportedly belonged to Marine Attack Squadron 211, based in Yuma, Arizona. VMA-211 had shifted its Harrier jump jets to Bastion from nearby Kandahar in July, in order to better support the British troops and Marines operating from Bastion. Harrier squadrons typically deploy with 10 jets, meaning all but two of VMA-211's planes are now out of action. Despite this, ISAF unconvincingly insisted there would be "no impact to ground or air operations from Camp Bastion."

Startlingly, the six destroyed Harriers represent no less than 1/15th of the Marines' entire inventory of the versatile, vertical-landing jets. The F-35B version of the stealthy Joint Strike Fighter is slated to replace the Harrier over the next 15 years.

Nine NATO personnel – eight military and one civilian – were injured in addition to the two Marines who died. One of those killed was from VMA-211, according to the San Diego Union-Tribune. Base defenders killed 14 of the attackers and captured one. "This information is subject to change as new details become available," ISAF warned.

The Bastion attack is not the first time insurgents have targeted NATO aircraft. Last month a rocket damaged an Air Force C-17 cargo plane assigned to carry Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey on his Afghanistan tour. Two maintainers were injured in that strike. And in 2005 a rocket barrage aimed at Kandahar Air Field destroyed a British Harrier and damaged another.

Nor is Friday's attack the first perpetrated by insurgents disguised as U.S. troops. In 2010, following a spate of such attacks, the Pentagon ordered the Army to begin treating stocks of uniforms as "sensitive" and remove them from "pilferable" ground resupply convoys moving through Pakistan. “There is evidence that the enemy is using pilfered out-garment uniform items to gain a tactical advantage," the Pentagon warned.

It's unclear to what extent that advantage factored into the Bastion attack. In any event, the death and destruction wrought on a heavily-defended NATO base by just 15 determined attackers is a chilling reminder of the insurgency's enduring potency.