Increasingly, it appears that the worst terrorist attack on an aircraft since September 11th took place on October 31 over the skies of Egypt. Evidence has begun to mount that the crash of a Russian jet in the Sinai desert, which resulted in the death of all 224 aboard, was the result of an explosion caused by a terrorist device. In the United States, this earth-shattering event has been greeted with a strange mix of confusion and ennui.

According to the European investigators who have been scrambling to identify what happened to Metrojet Flight 9268, the cockpit flight recorder audio reveals it was not a mechanical failure that brought the plane down. This revelation followed an unequivocal statement on Thursday from British Prime Minister David Cameron who, while hosting a visit with Egyptian President Abdul Fattah al-Sisi, said that “it looks increasingly likely” that a “terrorist bomb” took down the aircraft. American President Barack Obama confirmed that U.S. intelligence was taking that possibility
“very seriously.”

“There’s a possibility that there was a bomb on board,” Obama averred.

What followed these comments could only be described as chaos. A number of Western airlines halted flights over Sinai airspace, and Russia ceased all flights to the entire country of Egypt. Tens of thousands of European tourists, all racing to the transportation hub of Sharm el Sheikh, found they had been stranded. The United States Department of Homeland Security announced on Friday that a variety of new security measures would be applied to commercial flights departing from certain airports in the Middle East and transiting into America.

An Egyptian official told ABC News that local authorities believe that a functional explosive device having been somehow smuggled aboard that plane is the “most plausible scenario” and that technical malfunctions are now “at the bottom of their list of possible scenarios.”

If confirmed, this would represent the most successful terrorist attack on airplanes since 9/11. Al-Qaeda had hoped to duplicate its 2001 coup and sought on multiple occasions to attack aircraft. Those plots ranged from the hapless Richard “shoe bomber” Reid’s foiled plot, to Umar Farouk Abdulmutallab, the “underwear bomber,” who unsuccessfully tried to destroy Northwestern Flight 253 on Christmas Day in 2009, to the more serious plot to blow up five European airplanes over the Atlantic around the Christmas holiday last year. In 2012, the Central Intelligence Agency worked with foreign partners to disrupted a Yemen-based al-Qaeda plot to smuggle an experimental device that was designed to evade airport detection methods aboard a U.S.-bound flight. All of these operations failed.

Now, it seems as though a terrorist plot to get a bomb on board a European aircraft has finally succeeded. It was not, however, al-Qaeda that succeeded in this feat; it was the Islamic State in Iraq and Syria. U.S. officials who spoke to CNN reporter Barbara Starr on condition of anonymity told her on Wednesday that the explosion aboard this plan was most likely caused by a bomb planted “by ISIS or an affiliate.”

“The signs pointing to ISIS, another U.S. official said, are partially based on monitoring of internal messages of the terrorist group,” the report read. “Those messages are separate from public ISIS claims of responsibility, that official said.”

This should be generating more than a passing headline or two in the United States. Recall that some American cable networks devoted wall-to-wall coverage to a missing aircraft last year, even entertaining the possibility that a gravitational anomaly was responsible for its disappearance. Bizarrely, the very real prospect of renewed and unpreventable terrorist actors targeting and destroying passenger aircraft has not merited nearly the coverage it deserves.

One of the most troubling theories (due to its likelihood) is not that a special form of explosive that could evade detection methods was smuggled aboard this aircraft, but that an agent loyal to Islamist terrorists working with airport security facilitated this attack. The Metrojet attack could, as some have suggested, result in Russia stepping up its military campaign in Syria and beginning to target ISIS in earnest. Thus far, Russian aircraft have largely focused on striking anti-Assad, U.S.-aligned rebels and CIA weapons depots. It will almost certainly mean stepped up airport security in the West.

Given the likely far-reaching effects of this successful terrorist attack, the muted reaction to it in the United States is incongruous. It is the surest sign yet that Americans have again succumbed to complacency and a “September 10th” mentality.