Efficient cooperation between US and Pakistani intelligence services thwarted a potential terrorist "dirty bomb," attack. The world is a little safer from nutcases who would spread radioactive dust in populated areas for their own twisted ends. Well, maybe not quite.

We don't really know if the man the government is holding is a potential dirty bomber. But there are plenty of dirty bombs in the US already; some of them are regularly used by the US military.

A dirty bomb is not a true nuclear bomb, but instead radioactive material packed around a conventional bomb, semtex, or fertilizer and spread through the force of the explosion, contaminating an area, perhaps beyond repair.

One example of this type of weapon is the armor piercing shell regularly used by the military. Composed of a core of dense, "depleted uranium," these shells are capable of piercing heavy tank armor. Bursting into flame on impact, they spread radioactive uranium dust far and wide. Perhaps for accuracy of description the media should refer to them from now on as "dirty" armor piercing shells.

The bright side to an possible dirty bomb attack on US soil, according to the pundits, is that the government has a lot of experience and information regarding radiation exposure and nuclear fallout.

What pretty much all the major news outlets left out of their coverage is how exactly the US government got this confidence-inspiring collection of radiation exposure information.

They got it by exposing often unwitting human test subjects, of course. Soldiers directed to march into radioactive clouds unprotected. People (including mental patients and children) injected with plutonium. Intentional releases of radioactive iodine and other substances into the atmosphere to study their effects on the "downwind" population.

There are dirty bombers out there all right.

The experts say that the worst effect of a terrorist dirty bomb would likely be the ensuing panic. That's because the radiation unleashed would not immediately kill masses of people, but would merely increase the incidence of cancers slightly in the affected area. Somewhat in the same way that the leaks from Hanford, Three Mile Island, and other nuclear sites do. That is to say, the effects of a terrorist dirty bomb would be indistinguishable from the sort of negligence and accidents that characterize daily business in the nuclear power industry.

When it comes to the matter of where the terrorists would get the radioactive material for their bomb, the experts point to the some 5 million locations in the US where such material is stored or used. That's 100,000 point sources for each state. Not only could material be stolen from these sites, but they could themselves be blown up, spreading the material inside.

With 5 million radioactive sites already, it hardly seems necessary to use a bomb to spread it around a little more still. Simply doing nothing and allowing US nuclear policy to continue on its present course would assure the radiation poisoning of America.

Terrorists bent on wreaking nuclear, biological, and chemical havoc on the US could do worse than to spend their money supporting the Bush Administration's program. More arsenic in the water, more carcinogens in the atmosphere, more nuclear proliferation, more poisons all around.

Which brings up the question of the actual difference between terrorism and what we do, not only to other people, but to ourselves.

Apart from dirty bombs, counterterrorism agencies focus on cyberterrorism, aiming to thwart attacks on our infrastructure. Had the California energy crisis been caused by terrorists hacking into US computers, we would all be properly terrified. The authorities would take the most extreme measures imaginable. Since it was merely the result of good old American larceny, we demand institutional reforms.