Here’s what we know now that the House Benghazi Committee has issued its final report:   Libya had descended into chaos in September 2012. Benghazi, in particular was a no man’s land. And there’s no evidence that, once the assault on the U.S. compound in Benghazi began, there was anything U.S. forces could have done to prevent terrorists from murdering four Americans.

That’s exactly what we knew when the State Department’s Accountability Review Board issued its report on December 19, 2012 — two months after the attacks and nearly four years ago. It’s also what we knew when Hillary Clinton testified before the Senate and House foreign relations committees in January 2013, when several House and Senate committees concluded investigations into the tragedy in the last Congress and throughout Benghazi Committee Chairman Trey Gowdy’s leak-as-you-go probe.

It’s hard to be certain of that because the committee, in its zeal to get media coverage, apparently leaked parts of the report to news outlets under embargo with the promise of “exclusive” information. But most of what the committee peddled as “new” was actually old, irrelevant or trivial.

Here one example, which you can find prominently displayed on the committee’s website. 

“ With Ambassador Stevens missing, the White House convened a roughly two-hour meeting at 7:30 p.m., which resulted in action items focused on a YouTube video, and others containing the phrases ‘[i]f any deployment is made,’ and ‘Libya must agree to any deployment,’ and ‘[w]ill not deploy until order comes to go to either Tripoli or Benghazi.’”

This video conference was first detailed in the book “HRC: State Secrets and the Rebirth of Hillary Clinton,” which was published in February 2014. I know because I am one of the book’s two co-authors, along with Amie Parnes. While we did not report on the partial quotes in the committee’s bullet-pointed “news” nugget, we did report on the video meeting, its participants and the fact that officials from the White House, Pentagon, State Department and CIA were briefing each other.

The committee also reports as a first-of-its kind revelation that Ambassador Chris Stevens went to Benghazi because he wanted to provide the assessment Clinton needed to turn the temporary facility there into a permanent consulate. But Stevens’ No. 2 in Libya, Greg Hicks, testified to that before the House Oversight and Government Reform Committee several years ago. It’s simply not new information.

The committee does report some new details. For example, Vice Chairman of the Joint Chiefs of Staff Sandy Winnefeld had another official from the Pentagon join the video conference call because he was hosting a dinner at his house for foreign dignitaries. And, due to concerns for the safety of possible reinforcements and Americans on the ground, some troops had to switch from military to civilian dress a few times.

But none of those details have anything to do with the basic underlying truth: No one has presented a credible case that the Pentagon, the State Department or U.S. intelligence agencies could have saved either Stevens or Sean Smith — the two Americans who died in the initial attack — or the two contractors who were killed when a nearby CIA compound was shelled.

The failure of the committee to find new information is not an indictment of the conduct of the investigation. Some things are worth digging into, even if investigators aren’t able to discover new information or wrongdoing.  And the money spent by the Benghazi Committee — often cited by critics — is irrelevant compared to the fundamental truth about the panel: Its work ended up being largely duplicative.

There’s plenty of reason for Americans to question Clinton’s actions with regard to Libya. She stitched together the coalition that pummeled Moammar Gadhafi’s forces and helped persuade President Barack Obama to attack. She was certain rebels could take and maintain control. To this point, it hasn’t turned out how she planned.  Indeed, Libya descended into chaos after Gadhafi’s ouster, and the Benghazi attack was a heartbreaking symbol of how the nation had deteriorated.

But this investigation fell short of providing valuable new insights to the public about the murders or what can be done to prevent similar attacks in the future. The administration and other congressional committees already had done that work.  Yeah, the investigation was a partisan witch hunt.  But worse, the authors of Tuesday’s report pursued the probe long after it was clear it wouldn’t provide any real public benefit.