It was October 2012. Roei Elkabetz, a brigadier general for the Israel Defense Forces (IDF), was explaining his country's border policing strategies. In his PowerPoint presentation, a photo of the enclosure wall that isolates the Gaza Strip from Israel clicked onscreen. "We have learned lots from Gaza," he told the audience. "It's a great laboratory."

Elkabetz was speaking at a border technology conference and fair surrounded by a dazzling display of technology—the components of his boundary-building lab.