He warned China was seeking to create "client economies and governments" by exporting technology to countries around the world, and said these countries risked "mortgaging the future" by buying in Chinese technology with "hidden costs".He pointed to a series of examples including:- China's development of the BeiDou satellite system - a rival to the established GPS network which he said had been built into exports to more than 120 countries.He claimed it could be used to track individuals or combined with plans to knock out other countries' satellites in the event of a conflict- New standards for the internet proposed by China which would embed greater government control- Plans for Chinese digital currencies which he suggested were a sign of Beijing seeking to learn lessons from Russia's experience and insulate itself from the impact of sanctions.Sir Jeremy, who runs the agency which monitors communications and cyberspace, also called for a "grown-up" conversation about collaboration with China at UK universities.On concerns over the use of tactical nuclear weapons, he said in response to questions after his lecture that any talk of their use was "extremely dangerous" but that their use still appeared "hopefully a long way off"."