Washington, June 7 US lawmakers this week warned that a successful attack on the Global Positioning System (GPS) could severely disrupt the American economy, as a House panel examined growing threats from China and Russia and debated competing technologies to provide backup positioning, navigation and timing services.At a hearing of the House Energy and Commerce Subcommittee on Communications and Technology, members of both parties agreed that GPS has become deeply embedded in modern life and that growing incidents of jamming and spoofing pose risks to national security, transportation networks, communications systems and critical infrastructure.During the hearing, Subcommittee Chairman Richard Hudson...