Inside the US National Cyber Mission Force, which has been deployed to 20 countries since 2018 to battle state-backed Russian, Chinese, and North Korean hackers (Gordon Corera/BBC)

Gordon Corera / BBC:
Inside the US National Cyber Mission Force, which has been deployed to 20 countries since 2018 to battle state-backed Russian, Chinese, and North Korean hackers  —  Russia failed to take down Ukrainian computer systems with a massive cyber-attack when it invaded this year, despite many analysts' predictions.