I Guess that the word "Khorasan" is Arabic for "Gulf of Tonkin"

Glenn Greenwald and Murtaza Hussain make a rather compelling case for The Khorasan Group being a construct of the Obama Administration to provide a legal fig leaf for dropping bombs on Syria:

As the Obama administration prepared to bomb Syria without Congressional or U.N. authorization, it faced two problems. The first was the difficulty of sustaining public support for a new years-long war against ISIS, a group that clearly posed no imminent threat to the “homeland.” A second was the lack of legal justification for launching a new bombing campaign with no viable claim of self-defense or U.N. approval.

The solution to both problems was found in the wholesale concoction of a brand new terror threat that was branded “The Khorasan Group.” After spending weeks depicting ISIS as an unprecedented threat – too radical even for Al Qaeda! – administration officials suddenly began spoon-feeding their favorite media organizations and national security journalists tales of a secret group that was even scarier and more threatening than ISIS, one that posed a direct and immediate threat to the American Homeland. Seemingly out of nowhere, a new terror group was created in media lore.

………

AP warned Americans that “the fear is that the Khorasan militants will provide these sophisticated explosives to their Western recruits who could sneak them onto U.S.-bound flights.” It explained that although ISIS has received most of the attention, the Khorasan Group “is considered the more immediate threat.”
………

The genesis of the name was itself scary: “Khorasan refers to a province under the Islamic caliphate, or religious empire, of old that included parts of Afghanistan.” AP depicted the U.S. officials who were feeding them the narrative as engaging in some sort of act of brave, unauthorized truth-telling: “many U.S. officials interviewed for this story would not be quoted by name talking about what they said was highly classified intelligence.”

………

Orr then announced that while ISIS is “dominating headlines and terrorist propaganda,” Orr’s “sources” warn of “a more immediate threat to the U.S. Homeland.” As Orr spoke, CBS flashed alternating video showing scary Muslims in Syria and innocent westerners waiting in line at airports, as he intoned that U.S. officials have ordered “enhanced screening” for “hidden explosives.” This is all coming, Orr explained, from ”an emerging threat in Syria” where “hardened terrorists” are building “hard to detect bombs.”
………

On September 25, the New York Times – just days after hyping the Khorasan threat to the homeland – wrote that “the group’s evolution from obscurity to infamy has been sudden.” And the Paper of Record began, for the first time, to note how little evidence actually existed for all those claims about the imminent threats posed to the homeland:

American officials have given differing accounts about just how close the group was to mounting an attack, and about what chance any plot had of success. One senior American official on Wednesday described the Khorasan plotting as “aspirational” and said that there did not yet seem to be a concrete plan in the works.

Literally within a matter of days, we went from “perhaps in its final stages of planning its attack” (CNN) to “plotting as ‘aspirational’” and “there did not yet seem to be a concrete plan in the works” (NYT).

(emphasis mine)

What's more, the folks at The Intercept also noted that no one ever heard of the group before it was a justification for the airstrikes:

Even more remarkable, it turns out the very existence of an actual “Khorasan Group” was to some degree an invention of the American government. NBC’s Engel, the day after he reported on the U.S. Government’s claims about the group for Nightly News, seemed to have serious second thoughts about the group’s existence, tweeting:

Syrian activists telling us theyve never heard of Khorasan or its leader
— Richard Engel (@RichardEngel) September 24, 2014

Indeed, a NEXIS search for the group found almost no mentions of its name prior to the September 13 AP article based on anonymous officials. There was one oblique reference to it in a July 31 CNN op-ed by Peter Bergen. The other mention was an article in the LA Times from two weeks earlier about Pakistan which mentioned the group’s name as something quite different than how it’s being used now: as “the intelligence wing of the powerful Pakistani Taliban faction led by Hafiz Gul Bahadur.” Tim Shorrock noted that the name appears in a 2011 hacked Stratfor email published by WikiLeaks, referencing a Dawn article that depicts them as a Pakistan-based group which was fighting against and “expelled by” (not “led by”) Bahadur.

There are serious questions about whether the Khorasan Group even exists in any meaningful or identifiable manner. Aki Peritz, a CIA counterterrorism official until 2009, told Time: “I’d certainly never heard of this group while working at the agency,” while Obama’s former U.S. ambassador to Syria Robert Ford said: ”We used the term [Khorasan] inside the government, we don’t know where it came from….All I know is that they don’t call themselves that.” As the Intercept was finalizing this article, former terrorism federal prosecutor Andrew McCarthy wrote in National Review that the group was a scam: “You haven’t heard of the Khorosan Group because there isn’t one. It is a name the administration came up with, calculating that Khorosan … had sufficient connection to jihadist lore that no one would call the president on it.”

What happened here is all-too-familiar. The Obama administration needed propagandistic and legal rationale for bombing yet another predominantly Muslim country. While emotions over the ISIS beheading videos were high, they were not enough to sustain a lengthy new war.

So after spending weeks promoting ISIS as Worse Than Al Qaeda™, they unveiled a new, never-before-heard-of group that was Worse Than ISIS™. Overnight, as the first bombs on Syria fell, the endlessly helpful U.S. media mindlessly circulated the script they were given: this new group was composed of “hardened terrorists,” posed an “imminent” threat to the U.S. homeland, was in the “final stages” of plots to take down U.S. civilian aircraft, and could “launch more-coordinated and larger attacks on the West in the style of the 9/11 attacks from 2001.”"

As usual, anonymity was granted to U.S. officials to make these claims. As usual, there was almost no evidence for any of this. Nonetheless, American media outlets – eager, as always, to justify American wars - spewed all of this with very little skepticism. Worse, they did it by pretending that the U.S. Government was trying not to talk about all of this – too secret! – but they, as intrepid, digging journalists, managed to unearth it from their courageous “sources.” Once the damage was done, the evidence quickly emerged about what a sham this all was. But, as always with these government/media propaganda campaigns, the truth emerged only when it’s impotent.

This sounds an awful lot like George W. Bush saying, "Facing clear evidence of peril, we cannot wait for the final proof, the smoking gun that could come in the form of a mushroom cloud."

This is the product of the imperial consensus that emerged following the fall of the USSR, with a dash of venality and mendacity from the House of Saud.

I cannot help but think that we are close to seeing the end of the American imperium, and that it's fall will be not be pretty.