The billionaire, who primarily lives in Stockholm, just led a €600 million investment in Helsing, a 4-year-old, Munich-based defense tech company that is now valued at €12 billion, as first reported by the Financial Times and confirmed separately by TechCrunch. The deal makes it one of Europe’s most valuable privately held companies; it also highlights Europe’s scramble to build its own military muscle as the world grows messier and the U.S. turns inward. […] But what started as an AI software company has grown much more ambitious. Helsing is now building its own strike drones and aircraft and said it’s working on a fleet of unmanned mini submarines in order to improve naval surveillance.