Angelina Jolie at the afterparty for the premiere of “In The Land of Blood and Honey” at the United States Holocaust Memorial Museum on Tuesday. (Kris Connor/Film District)

It was nearly midnight, we hadn’t eaten dinner, and we were desperate to get off of these shoes. But were we allowed to leave the party before the movie stars depart?

This usually isn’t a problem. The bigger the star, the briefer their cameo at the soirée. Many guests didn’t even really expect Angelina Jolie and Brad Pitt to show up at the elite after-party for her red-carpet premiere at the Holocaust Museum Tuesday night — yet they not only showed up, they closed it down.

Jolie meets Ruth Bader Ginsburg. (Kris Connor/Film District)

Yes, a red-carpet premiere at the Holocaust Museum — no literal carpet, but a roped-off “arrivals” ceremony for paparazzi — and if it’s hard to wrap your head around, well, it’s the kind of thing that happens when Angelina comes to town. For her directorial debut, the actress/globetrotting humanitarian picked a weighty topic — the Bosnian War — and is rolling it out in highbrow style. An NYC debut was hosted by the Council on Foreign Relations (she’s a member); in Washington, she packed the screening room with policy wonks, diplomats and White House staffers. (Also: Ruth Bader Ginsburg, Chris Dodd, Tim Shriver, Susan Eisenhower, Michael Chertoff, Jack DeGioia.)

(**Read also: Angelina Jolie on “In the Land of Blood and Honey”, Ann Hornday, 1/13/12)

After solemn opening remarks from museum director Sara Jane Bloomfield and Tom Carver of the Carnegie Endowment for International Peace (the former war correspondent vouched that Jolie’s movie “does smell and feel like the real thing”), the star took the stage in a pale gold frock. She read earnestly from notes, hailing her Bosnian cast as if they were a cause (“to make this film they came together across ethnic lines”), and told the audience she looked forward “to hearing your reactions.”

And then, of course, she bailed, as stars always do during the screening — off to Charlie Palmer for dinner with Brad and Valerie Jarrett. (On Wednesday, the A-listers paid a visit to the White House to see President Obama.)

Goran Kostic (Kris Connor/Film District)

When she returned for the afterparty: Total Angemania! The pedigreed crowd pressed in around her — desperate to have a word with her or a photo with her, or just watch her talk. Pitt (looking like an old British rock star: long hair, scruff, three-piece suit, walking stick for the ACL he bruised on a skiing trip with the kids) moved to the far side of the room, breaking off his own smaller mob, letting it be her night.

We crowded in alongside foreign-policy pundit Steven Clemons, waiting in line as C. Boyden Gray had his moment with the star. “I loved it!” Clemons said of the movie, with some surprise. “I thought it would be a vanity project.”

Jolie kept her coat on like she was headed for the door — but didn’t. An hour later, as the crowd thinned, she was still there, holding court with some NGO types about her recent Charlie Rose interview. “I love Charlie,” she said, though “he’s interviewing you and you can’t tell if he’s seen the movie!” She moved on to Jay Carney and Claire Shipman, talking about getting the kids together on the next trip to D.C.

Nearby stood one of her stars, Goran Kostic,. Is it always this crazy when you go somewhere with Angelina Jolie?

This is nice and cultured and organized,” he told us. “At other stops you just get washed away by people.”

Brad Pitt with guests at Tuesday’s premiere. (Kris Connor /Film District)

Jolie with guests at Tuesday’s premiere. (Kris Connor/Film District )