It was 2 a.m. on a Tuesday when the raid began at the Eyewitness War Museum in the town of Beek, the Netherlands.

First, a group of thieves teased open the museum’s front gate. “You can see it on our cameras,” Wim Seelen, the museum’s director, said in a telephone interview.

But then, they disappeared.

An hour later, the burglars returned in several estate cars. In a scene reminiscent of a heist movie, they spread out tires across the highway that runs past the museum to create a roadblock, and parked a fake police car beside it, so it looked official.

Over the next five minutes, the group — maybe 12 people in total, Mr. Seelen said — battered down the museum’s front door, broke display cabinets and took what they’d come for: nine mannequins wearing rare Nazi uniforms. The outfits included one worn by Hitler’s personal chef, and another by a high-ranking member of the S.S.

The robbers took other items of World War II memorabilia, Mr. Seelen said, with the haul worth about $1.5 million in total.

“It was done with military precision,” he added. The museum’s alarms went off, but the police — held up by the roadblock — arrived too late to catch anyone.

“Of course, I’m terrified it will happen again,” Mr. Seelen said.