American anti-tank gunners in the Gulf War raved about it. It was their "silver bullet," piercing the armor of Iraq's Soviet-made tanks as if they were soda cans.
Gunners became accustomed to first-round, tank-fired shots that ignited Iraqi T-72s with such force and fire that the result was dubbed "Dante's Inferno." Fired from A-10 "tank-buster" planes in 30-mm form, this bullet stopped armored convoys in their tracks.
This is the tale of a high-density bullet made of depleted uranium (DU), a low-level radioactive waste left over from the making of nuclear fuel and bombs. Because of its success, DU has already become a staple of the US military's arsenal. It has been sold by the US and Russia to other forces all over the world.
In the war over Kosovo today, NATO has loaded DU rounds into the guns of Air Force A-10s. So far, the Air Force says, this highly effective antitank ordnance has not yet been used.
Wherever it is fired, it leaves a radioactive trail. A Monitor investigation of the Persian Gulf war zone, where this bullet saw its first live action in 1991, found that it has left the desert sprinkled with radioactive and chemically toxic dust.
Clues in how DU is handled
How dangerous is this unseen residue once the battle is over - whether in Iraq's southern desert or in a Kosovo to which hundreds of thousands of refugees are meant to return?
The US military has given mixed signals. A series of Pentagon reports and regulations cite serious health risks from depleted uranium, and still stipulate stringent, moon-suit type protective gear when approaching objects hit with DU bullets.
And the Nuclear Regulatory Commission requires the military to have a license to make or test fire a single DU round. In part because of safety and environment concerns over DU, the US Navy opted to use tungsten for its armor-piercing bullets.
But Pentagon officials today downplay that risk and cite other Pentagon reports that back their view. They confirm that thousands of US soldiers were "unnecessarily exposed" to DU in the Gulf, adding their view that those exposures were "not medically significant."
In Iraq, however, physicians describe a sharp upward spike after the Gulf War in the kind of health diagnoses - such as cancer - associated with exposure to radiation. Iraqi veterans interviewed by the Monitor supported those claims, if only anecdotally.
Perhaps one cause among many
But any increase in Iraqi health problems may have another cause, or many causes. The Gulf War was the scene of a "toxic soup" of dangerous chemicals. The Iraqis, and some American physicians and scientists, argue that DU is one of the most dangerous.
Indeed, some Western scientists who have examined DU believe that it could be one of the factors behind Gulf War syndrome - the much-studied, little understood set of symptoms claimed by as many as 1 in 7 US Gulf War veterans.
The American military designed DU bullets in the 1970s, during the cold war, to counter Moscow's advanced T-72 tanks. Denser than lead, DU burns and self-sharpens when it hits a hard target and scorches its way through inch after inch of armor in, literally, a flash.
American forces - and, to a very small degree, their British allies - fired the 320 tons of DU that was shot across the deserts of Kuwait and southern Iraq, where most of it still lies.
But it does not lie quietly. A Monitor reporter who traveled throughout the region watched a radiation detector carried over parts of those battlefields register about 35 times normal background radiation. Portions of old tanks "killed" with DU bullets showed radiation levels 50 times above background - results similar to what US Army teams found during the war.
Risks as a breathable dust
When DU is protectively encased and carefully handled, its health risks are considered small. So if DU is outside the body, these are not especially dangerous levels of radiation.
But when it smashes at Mach II into metal, DU burns and pulverizes into dust that can soar in the heat column of a flaming tank and waft for miles on the desert wind.
It is when this dust is inhaled or ingested that it becomes most dangerous as a radioactive substance and a toxic heavy metal, some experts say.
So far, DU bullets have received only limited public attention, though the Pentagon predicts that every future battlefield is likely to be strewn with their residue.
Reporting from Iraq, Kuwait, and the US, this Monitor series examines the possible long-term effects of this powerful spinoff of the nuclear age.
If there is a connection between human suffering and DU, then its use in the future will mean that lands of conflict will remain contaminated for the 4.5 billion years - a figure comparable to the age of the solar system - that DU remains radioactive.