Explainer: what is Volt Typhoon and why is it the 'defining threat of our generation'?

Relations between the US and China - particularly over Beijing's threats to annex Taiwan - have plummeted in recent years, prompting growing concern about the potential for hostilities or all-out conflict. So recent revelations that a Chinese hacking network known as Volt Typhoon had been lying dormant inside US critical infrastructure for as long as five years have sparked considerable alarm. The network exploited US technological and security weaknesses. But rather than stealing secrets, US and allied intelligence services said it was focused on "pre-positioning" itself for future acts of sabotage. FBI director Christopher Wray told a US committee hearing…