The United States is drawing up plans to keep Russia and others from being spooked into millennium bug-related "nightmare" military scenarios, a top Pentagon official said Thursday.

In a stark warning about the year 2000 computer glitch threat, Deputy Defense Secretary John Hamre cited a need to calm Russian nuclear forces in particular if the "bug" caused their computers to crash, as many systems may fail worldwide.He told the Senate Armed Services Committee that cash-strapped Russian forces were relying more and more on nuclear weapons "as a safeguard for their national security. And their early warning system is fragile," he said.

Such systems, heavily reliant on computers to mesh data from satellites, radars and other sensors, are used by Russia and the United States to monitor impending threats such as missile launches and unidentified aircraft.

He said Defense Secretary William Cohen ordered plans drawn up for sharing early warning information so "we don't enter into a nightmare condition where everybody is all of a sudden uncertain, and their screens go blank."

"That would be a very worrisome environment for all of us," he said, adding the idea was to share data not only with Russia, America's old Cold War foe, but with other, unspecified nations.

A formal proposal was to be ready later this summer, he added. He said Asian countries and nations of the old Soviet bloc were lagging the most in rewriting old computer code to cope with the date switch.

Hamre said Russian forces lacked a program to deal with the so-called Y2K problem - the inability of many computers to interpret correctly the century that dawns in 18 months.