Officials around the world recognise the need to deal with the growing threat of cyberwar. Many countries, including the US, are developing weapons for it, like “logic bombs” that can be hidden in computers to halt them at crucial times or damage circuitry; “botnets” that can disable or spy on websites; or microwave radiation devices that can burn out computer circuits miles away. The Pentagon is planning a military command to prepare for both defence and offensive computer warfare.