Since the end of the Cold War, the defense industry and its congressional allies have been quietly campaigning for a new type of nuclear weapon. Rather than relying on big bombs intended to annihilate entire cities, they want to develop "mini-nukes" and other small warheads designed to demolish underground bunkers or buried stores of chemical or biological agents. Warning that the current stockpile was "not developed with this mission in mind," the Defense Department issued a report last summer explaining that "lower yield" weapons could achieve "needed neutralization."
Now, in the wake of Sept. 11, the Bush administration is moving to add a smaller bomb to America's nuclear arsenal. The plans became public in March, when the media obtained a classified Pentagon report calling for the development of low-yield weapons for use in battlefield situations. But the news reports did not point out that by then the president's budget already included up to $15 million to study designs for what it calls a Robust Nuclear Earth Penetrator -- a weapon envisioned by its backers as a "bunker buster." Although the precise size of its payload has yet to be determined, the Penetrator is intended to give military strategists a new option: a deeply burrowing nuke specifically designed for use in otherwise conventional conflicts.
There's only one hitch in the administration's plan: In 1994, Congress banned the research and development of any new low-yield nuclear weapons. Since then, the defense industry has essentially been working around the law, insisting that it wants only to "modify" and "package" existing weapons to deliver small nuclear payloads. Last year, for example, an earth-burrowing "penetrator" that could be equipped with a nuclear warhead was patented by Sandia Corporation, a subsidiary of Lockheed Martin. The company, which runs the Sandia National Laboratories in New Mexico, claims the weapon can punch through up to 35 feet of reinforced concrete. C. Paul Robinson, the director of Sandia, told reporters that such firepower could be used to destroy underground bunkers in Afghanistan. "By putting a nuclear warhead on one of those weapons instead of high explosives, you would multiply the explosive power by a factor of more than a million," said Robinson, who also chairs an advisory council of the US Strategic Command.
At a hearing of the Senate Armed Services Committee in February, the administration insisted that its plan to study designs for such weapons does not violate the ban on nuclear research. John Gordon, head of the National Nuclear Security Administration, confirmed that he is setting up design teams at each of the nation's three nuclear labs -- Sandia, Los Alamos, and Lawrence Livermore -- but added that the scientists would only "think about and explore what might be possible." When lawmakers expressed concern that the administration is effectively changing weapons policy without consulting Congress, Undersecretary of Defense Douglas Feith assured them that the design teams will work only on a "straight modification of an existing system that's out there now, packaged in a way that could penetrate."
Such carefully phrased distinctions have done little to mollify those who fear that a low-yield bomb will undercut efforts to defuse a new arms race. In February, 76 members of Congress sent a letter to President Bush, expressing concern that any development of mini-nukes would send a signal "that the US is abandoning international efforts to stem the proliferation of nuclear weapons." Lawmakers expect the administration to ask Congress to lift the research ban entirely, enabling designers to move weapons like the Penetrator into production more quickly.
Since 1978, US policy has stipulated that nuclear weapons will not be used against nonnuclear countries unless they attack the United States in alliance with nuclear-armed nations. But the classified Pentagon report in March praised the "greater flexibility" offered by low-yield weapons and instructed the military to prepare contingency plans for using nuclear warheads in other conflicts that could involve weapons of mass destruction, including clashes between Arabs and Israelis or North and South Korea. After the report was leaked to the media, the administration quickly backtracked, insisting that the old policy remains in effect.
Lost in the debate has been any discussion of the potential effects of smaller nuclear bombs. Low-yield weapons are supposed to reduce collateral damage by delivering warheads of less than five kilotons -- about a third the size of the bomb used on Hiroshima.
But even with the smaller payloads, mini-nukes could kill anyone within a few miles of a targeted bunker. Initial tests of Sandia's new earth-burrowing weapon, for example, show that it blasts only 12 feet into concrete -- not nearly deep enough to prevent deadly nuclear fallout. "The physics is simple enough," says Robert Nelson, a physicist at Princeton University's Program for Science and Global Security. "To completely contain a one-kiloton nuclear explosion, you would have to go at least 300 feet."
With the Bush administration refusing to sign an international moratorium on nuclear testing, congressional opponents fear that developing smaller bombs sends the wrong signal to other nations eager to up the nuclear ante. "The last thing the terror-ravaged world needs right now is a new nuclear threat," says Rep. Edward Markey (D-Mass.), who sponsored the congressional letter to Bush. "How can we discourage India and Pakistan from using their nuclear weapons against each other while we're pursuing a whole new generation of weapons at home?"