It has considered manipulating cyberspace to disable an enemy air defence network without firing a shot, shut off power and phone services in major cities, feed false information about troop locations into an adversary's computers and morph video images (to cause confusion) on to foreign broadcast stations, the Washington Post reported today.

The US, said the Post, is intent on ``developing more powerful weapons for penetrating enemy computer networks.''

It continued: ``Not since the advent of nuclear bombs half a century ago have national security officials confronted weapons with such potential to alter the means for waging war, according to those involved in theplanning.''

The full extent of US offensive capabilities, said the daily, is among the most tightly held national security secrets. According to various accounts, the government has explored ways of planting computer viruses or ``logic bombs'' in foreign networks to sow confusion and disruptionInterestingly, coming as a case to the point, a former US Marine General has claimed that Washinton had incapacitated the computers of India and Pakistan two years ago, preventing a possible nuclear war between the two countries.

Assuming the two South Asian neighbours possessed nuclear weapons, Washington conducted a secret military exercise two years before New Delhi and Islamabad detonated nuclear tests, Washington Post said quoting Marine General John Sheehan and added the computers were rendered incapable by long-range cyber war.

Sheehan, who headed the Atlantic Command and an expert in information operation until his retirement, told the Post that the US was also assumed to have gained access to theinformation systems of the two nations. ``I said to the excercise group, as a matter of policy, do you want to alter their (India and Pakistan) command and control capability to the point where neither side has a clear picture of the battlefield, thereby pre-empting their use of nuclear weapons?"