In a secret blueprint given to Congress, the Pentagon warns of a need for the US to build small nuclear bombs for potential use against an enemy that sets off - or even just develops - either a biological or chemical weapon.
So far, the Nuclear Posture Review isn't a plan of action. President Bush and Congress must decide whether to make such new types of mini-nukes, and when to use them. That could take five years.
But news of the idea has sparked a debate on the military and moral wisdom of using the "nonconventional" weapon of a nuclear device (no matter how small) against a "nonconventional" weapon of mass destruction (no matter how big). In particular, a new nuclear device might penetrate chemical or biological weapons facilities underground.
The debate is not exactly new. The US deployed tactical nuclear weapons in West Europe in case of a Soviet land invasion. What's new is the suggestion that a preemptive strike with a nuclear device might be needed if a terrorist-minded nation gets close to deploying weapons of mass destruction.
Even before Sept. 11, the Bush administration contended that the mere possession of mini-nukes by the US would be a "hedge" to deter countries from developing chemical or biological weapons. Since then, the risk of such attacks seems more plausible.
"If the US is to have a flexible deterrent, it must be able to adapt its nuclear forces to changing strategic conditions," John Gordon, US under- secretary for nuclear security, told Congress last month.
As a military strategy to defend the US or its allies, the Pentagon may be right. But the administration must also weigh the long-term effects of such a course.
Will it justify other nations' obtaining mini-nukes? What happens to the Nuclear Nonproliferation Treaty and its grand bargain that nuclear nations not hit non-nuclear ones in return for those nations not having such weapons? How widespread would be the damage from these bombs? And can they be made without live testing?
The answers to such questions should not be as secret as this Pentagon paper. Congress, as well as President Bush, can educate Americans about a shift in nuclear strategy, and its implications. Public debate can help lead to the strongest defense.