New Delhi, July 22 -- WASHINGTON - Every third professional-grade drone currently used by American law enforcement or emergency services carries a DJI logo. The Federal Communications Commission moved on Tuesday to draw a line through that market share, proposing rules that would bar imports of advanced military-grade drones from Chinese manufacturers. The two companies named in the proposal - DJI and Autel Robotics - are the dominant suppliers of drone systems equipped with the swarming and thermal imaging capabilities that have become standard in military and paramilitary operations worldwide.

The FCC's stated rationale is the need to "secure the drone supply chain." What that means in practice is that a company responsible for an esti...