Germany's domestic intelligence agency, the Federal Office for the Protection of the Constitution (BfV), has issued warnings to defence companies, start-ups, and research institutions about a surge in Russian-linked espionage and sabotage activity, with 321 suspected sabotage cases recorded in 2025 alone. Recent arrests include two alleged spies who passed information about a German drone manufacturer to Russian intelligence, as well as a Ukrainian national accused of spying on a former fighter in Ukraine on behalf of Moscow. The warnings come as Germany's defence sector expands rapidly — with firms like Rheinmetall and Quantum Systems scaling up production — raising concerns that new industry entrants are particularly vulnerable; the government adopted a national economic protection strategy in mid-March to harden defences against what officials describe as an increasingly acute hybrid threat.