The US government is developing guidance for determining when and how the US would launch cyber-attacks against enemy computer networks.

According to the Washington Post, the strategic guidance will be similar to that which has governed the use of nuclear weapons since World War II.

So far the Pentagon has lacked presidential rules for deciding the circumstances under which such attacks would be launched.

Neither is it determined who should authorise and conduct them, and what would be considered legitimate targets.

The guidance is being prepared amid speculation that the Pentagon is considering some form of cyber-attack against Iraq if the president decides to go to war.

The Post reported that the extent of US electronic warfare capabilities is even more closely guarded than its nuclear capabilities.

Many of the plans are known only to small groups, which has previously inhibited the drafting of general policy and specific rules of engagement.