WITH ALL THE brouhaha about recent nuclear tests in India and Pakistan, it is interesting to learn what the United States - a founding member of the nuclear club - spent on developing and maintaining its nuclear arsenal.

Surprisingly enough, our government never kept track of the cumulative cost. It took a private research group, the Brookings Institute, to come up with a figure of $5.5 trillion in a just-released study called "Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons since 1940."When the estimated future-year costs for dismantling these weapons and disposing of nuclear waste are added, the total rises to more than $5.8 trillion - a figure so staggering that if it were measured in a stack of $1 bills, it would stretch 459,000 miles, to the moon and nearly back again.

Four years of extensive research, including access to previously classified documents, convinced Stephen Schwartz, director of the project, that government officials involved in the nuclear program didn't know, and didn't care, what they were spending, meaning they could not weigh the perceived benefits of having a nuclear deterrent against its actual cost.

"Nuclear deterrence is often compared to an insurance policy," said Schwartz. "But few homeowners would purchase insurance without knowing their annual premiums." Budgetary data is so skimpy or unavailable, he added, that our nuclear policy could be construed as "fiscally and politically unaccountable."

Despite its commitment to disarmament, the Clinton administration acknowledges a need for nuclear weapons to deter attacks by "rogue" states such as Libya, Iran, Iraq and North Korea. And the Strategic Command in charge of our nuclear arsenal says an "irrational and vindictive" demeanor helps cow potential enemies.

Echoes of the Cold War?