As United Nations inspectors fan out across Iraq - looking for evidence of Saddam Hussein's secret arsenal - the United States is rethinking the future of its own weapons of mass destruction.
Among the issues being discussed by US officials and the experts who advise them in this era of stateless terrorism and other forms of "unconventional warfare" are these: The resumption of nuclear weapons testing; ambivalence over controlling chemical and biological weapons at a time when advancing technology offers new opportunities to control the battlefield; and the possible development of tactical nuclear bombs to go after the kind of hardened targets that more than 70 countries - especially Iraq - now use to hide their most threatening weapons.
All of this would be happening even if the terrorist attacks of 9/11 had not occurred, even if war with Iraq were not as close as it is today. But the earthshaking events that have marked the beginning of the 21st century focus attention on the most intimidating military assets belonging to the world's lone superpower.
The US hasn't test-fired any nuclear devices since 1992. Officials figure it would take two to three years to be ready to resume testing. The administration wants to reduce that to a shorter period - not only to ensure that its aging stockpile of warheads is dependable, but also to allow the testing of any newly designed weapons.
The Pentagon's congressionally mandated Nuclear Posture Review calls for a "revitalized nuclear weapons complex that will ... be able, if directed, to design, develop, manufacture, and certify new warheads in response to new national requirements; and maintain readiness to resume underground nuclear testing if required."
More recently, a senior official urged reconsideration of the 10-year US moratorium on testing.
"We will need to refurbish several aging weapons systems," said defense undersecretary Edward Aldridge in an October memo to senior nuclear policymakers. "We must also be prepared to respond to new nuclear-weapon requirements in the future." Congress recently authorized the nation's nuclear weapons labs to weigh the benefits and costs of being able to test such weapons within six months.
While highly precise conventional arms - laser-guided bolts from the blue - made headlines in Afghanistan, many experts say they will never completely replace nuclear weapons.
"To ensure that enemy facilities or forces are knocked out and cannot be reconstituted, attacks with nuclear weapons may be necessary," the National Institute for Public Policy in Fairfax, Va., reported last year.
"The United States may need to field simple, low-yield, precision-guided nuclear weapons for possible use against select hardened targets such as underground biological weapons."
Several of that report's authors are now officials in the Bush administration, including Deputy National Security Adviser Stephen Hadley and Defense Science Board chairman William Schneider.
One of the attractions of small nuclear weapons, in the eyes of some theorists, is that they can more effectively destroy biological or chemical stockpiles than can conventional explosives.
In Geneva recently, Stephen Rademaker. US assistant secretary of state for arms control, said he was "very pleased" with international adoption of measures to strengthen the Biological Weapons Convention. He warned, however, that the 1972 treaty banning such weapons is "inherently unverifiable." This implies that the US needs to know as much as possible about any biological or chemical threats it may face.
The difficulty here is that even preparing to defend against such weapons requires research on the weapons themselves. In its examination of biomedical sciences and the pharmaceutical industry - both involved in Pentagon projects - the Federation of American Scientists reports that "an immense amount of time and money [is] being invested" in new technologies that could "significantly complicate the control of chemical and biological weapons."
Arms-control advocates also worry that defending against such weapons - especially those in underground bunkers - may increase the pressure to develop small,tactical nuclear weapons.
At this point, although official discussions have escalated, there is no rush to resume a nuclear arms race that had abated in recent years.
"Candidly, I cannot detect any plausible nuclear warfighting scenarios in the 'axis of evil' context," says John Pike, director of Globalsecurity.org, an analysis organization in Alexandria, Va., (referring to Bush's characterization of Iran, Iraq, and North Korea). "I am guessing that much of this is a discussion about [China]."
As is often the case with what could be a politically wrenching change in military strategy and doctrine, those in uniform tend to be more cautious than their civilian bosses. "In my experience, there is little to zero interest among military leaders in actually using nuclear weapons," says Larry Seaquist, a retired Navy warship captain and Pentagon strategist. "They recognize that nuclear employment, by breaking the half-century taboo since the two weapons used [on Japan] in 1945, would take us into a whole new world."
"They also recognize that the calculus of nuclear weapon use is totally different in these rogue-nation situations like Iraq than it was in the cold war," says Captain Seaquist. In other words, the old balance-of-terror nuclear regime of "mutual assured destruction" that kept the United States and the former Soviet Union from blowing each other up doesn't necessarily work with rogue states such as Iraq or with stateless terrorist organizations such as Osama bin Laden's Al Qaeda.