The White House has released emails on the misleading talking points created after the September 11, 2012 attack on the U.S. facility in Benghazi. Top officials have testified before Congress. More are coming, some under subpoena. All that activity means the public knows more than ever — although still not enough — about what went on at the State Department before and after the attack.

But when it comes to the attack itself, the American people are still in the dark, more than eight months after four Americans, including Ambassador Christopher Stevens, died in Benghazi. That is because key aspects of what happened from a military point of view — including the most basic question of what U.S. forces could and could not do to help Americans under attack — remain classified.

The House Armed Services Committee received a briefing from Pentagon officials last week about the military side of Benghazi. In a letter demanding the briefing, Chairman Buck McKeon told Secretary of Defense Chuck Hagel that he remains “deeply concerned” by the lack of information available about the hours Americans were under attack. McKeon said he wanted to know what aircraft the U.S. had in the region that might have come to the Americans’ aid; where those planes were; whether they were armed or could have been armed; whether they would have needed refueling; the presence of un-manned aircraft, armed and unarmed; the status of various U.S. emergency response teams; and the decisions commanders at all levels made in deciding to deploy or not deploy those assets.

Last Wednesday, McKeon got at least some of the answers to his questions. But it all remains a secret. “Everything that was said was classified,” says one Hill source. “At one point, it even moved up to a higher level of classification. Members had four hours to really drill down on what they wanted to know.”

Lawmakers apparently learned a lot, but not the public. What fighter aircraft were available to go to Benghazi, either from a U.S. base in Sicily or elsewhere? It’s classified. What other planes? Classified. What about drones, especially armed ones, in addition to the unarmed aircraft the Pentagon has said was sent to the site shortly after the attack began? That’s classified, too.

What about the precise movements and locations of those American emergency response teams? Classified. Navy ships? Classified. What about the role that fear of inflicting civilian casualties on the ground in Libya might have played in decision-making? Classified.

It’s all under wraps, at least for now. McKeon’s committee has had classified sessions before, going back to a hearing held not long after the attack. There have been other classified briefings, as well. Whatever answers the chairman has gotten remain secret.

McKeon did contribute to the “Progress Report” on the Benghazi affair issued last month by House Speaker John Boehner. The report contains a brief section laying out, in mostly general terms, what the Pentagon did in response to the attack. But there is not nearly enough information for the public to piece together a complete picture of what happened. And even the bare-bones information in the House report is more than is included in the unclassified State Department Accountability Review Board account.

Should so many military aspects of the Benghazi attack remain classified? Some knowledgeable sources think not, or at least not all of it. So far, though, the Pentagon thinks so, and McKeon is going along. “Part of the nature of our oversight is that the questions we’re asking are sensitive and classified, and the answers we get back are by and large classified,” says the source. “We’re trying to get them de-classified because we think this deserves a full public hearing.”

Maybe that will happen. But until it does, the American people will remain out of the loop about what happened in those very intense hours of last September 11.