Britain's frontline fighters could be blown out of the water by cyber-attackers sitting at computers, MPs warned today.
The Commons defence committee said armed forces are so dependent on information technology they could be "fatally compromised" by a byte blitz.
It reckoned a cyber threat to security had the ability to evolve at "almost unimaginable speed" and questioned whether the government could deal with it.
Ministers were urged to ensure contingency plans were in place after the committee heard entire combat units, such as aircraft and warships, could be knocked out.
Experts warned an enemy could target radar or satellites and increased use of unmanned drones and battlefield robots potentially added to vulnerability.
Shadow defence secretary Jim Murphy said: "This report is worrying. The government stands accused of complacency and lacking contingency planning."
Attacks such as yesterday's horrific murder in Woolwich didn't happen before the 'war on terror.' It's time we recognised the consequences of the conflicts we've unleashed