In 1987, the Toshiba Corporation of Japan was accused of illegally selling sophisticated propeller milling machinery to the Soviets through the Norwegian Kongsberg firm. The incident resulted in the arrest and prosecution of two senior executives, as well as the imposition of sanctions on the company by the US and Japan. It also resulted in quieter Soviet submarines principally the Akula Class.
It is also alleged that the Project 671RTMK Victor III subs incorporated a fully integrated submarine combat direction and fire control command system that ran on computers obtained from the Toshiba Corporation of Japan. This fire control system is said to be based on one developed for the Norwegian Ula class submarines.
So in recent news here and here, a Japanese employee of Toshiba Corporation has been caught selling confidential data to a Russian official. The leaked data referred to semiconductor technologies that could be used for jet fighter radar, missile guidance systems and submarine periscopes.
Industrial espionage is as much a national security risk as the Walker spy ring or those identified in the Cox Report.