US intelligence agencies have officially described the attack on the US Consulate in Benghazi, Libya on September 11 that killed four Americans as a planned terrorist attack carried out by militants friendly to Al Qaeda. That’s distinct from it being an Al Qaeda attack, though the decentralized (and also battered) nature of the organization means that such a thing doesn’t exist anymore.

This completes a slow evolution of US thinking about the attack, which initially was described as a spontaneous uprising based on an anti-Islam YouTube video, linked to other protests and riots outside US embassies and missions in other parts of the Muslim world. Over time, and with the aid of eyewitness reports that revealed no protest presence before the attack, the US determined that the Benghazi attack stood apart from those other incidents.

U.S. intelligence officials said the composition of the militant forces involved in the assault has become clearer over the past week and that analysts now think that two or three fighters affiliated with al-Qaeda in the Islamic Maghreb were involved.

“There are people who at least have some association with AQIM,” said a senior U.S. intelligence official who added that “it’s not so direct that you would say AQIM as an organization planned and carried this out.”

Instead, U.S. officials said a ­lesser-known Islamist group, ­Ansar al-Sharia, played a much larger role in sending fighters and providing weapons for the attack, which killed the U.S. ambassador and three other Americans. U.S. officials have previously cited suspicion of al-Qaeda connections to the attack.

The Libyan government has also labeled Ansar al Sharia as the culprit. For their part, that group has not taken responsibility for the attack, but said a splinter group of Ansar al Sharia members might have carried it out.

The Financial Times reports that Ansar al Sharia may simply be fresh branding for the same group of militants allied with al Qaeda, along with fundamentalist Salafist Islamists who favor religious law ruling over their homelands. Salafist militias have been responsible for attacks in Libya over the past several months, particularly at Sufi Muslim shrines and mosques. As for the links to other terrorist organizations, it gets a little hard to make the distinction:

Some observers have described Ansar al-Sharia as a new offensive by al-Qaeda under another name, designed to win back hearts and minds after the extremist network was sidelined by popular protests against authoritarian rule.

But while Yemen’s Ansar al-Sharia is believed to have been created by al-Qaeda, the North African groups do not appear to have a direct connection with the jihadist organization or share its global jihad agenda [...]

Aaron Zelin, a fellow at the Washington Institute for Near East Studies, says the rise of Ansar al-Sharia groups points to an end to al-Qaeda’s “unipolar” global jihad of the past decade, with jihadists acting locally, even if they think globally, and being more interested in providing services and governance.

“They are fighting in different lands using different means, but all for the same end, an approach better suited for the vagaries born of the Arab uprisings,” he wrote in Foreign Policy magazine.

So this is a different group with more local concerns, but exists on a continuum with other groups. Given the typical bluntness with how the US approaches the Muslim world, I’m not sure there’s a complete appreciation for the subtlety. About as close as you get is Leon Panetta saying “There’s a lot of different kinds of terrorism in that part of the world.”

What we do know is that the FBI cannot get further than Tripoli in the course of their investigation, owing to security fears. The Embassy there just removed more non-essential personnel from the country, and FBI agents have interviewed witnesses in cars outside the Embassy instead of bringing them inside. This difficulty in getting within 400 miles of the attack site suggests that maybe the whole picture has not been pieced together yet.

And yet the stakes are high. Calling this a terrorist attack will undoubtedly put pressure on the Administration to strike a posture of “bringing those responsible to justice.” It could open a new front in the war on terror, which never really ended. Before intelligence changes their mind again, maybe they should get more of a clear sense of what happened.