Concerns are growing that Al Qaeda or a related group could detonate a "dirty bomb" that would spew radioactive fallout across an American or European city, according to intelligence analysts, diplomats and independent nuclear experts.
The United Nations nuclear watchdog agency is investigating potential links between the atomic programs of Iran and Pakistan after discovering that the secret Iranian uranium-enrichment program used technology identical to Pakistani plans, diplomats said.
Israel has modified American-supplied cruise missiles to carry nuclear warheads on submarines, giving the Middle East's only nuclear power the ability to launch atomic weapons from land, air and beneath the sea, according to senior Bush administration and Israeli officials.
International inspectors confirmed that particles of highly enriched uranium had been discovered in two separate samples taken at a nuclear facility in Iran, raising the possibility that Tehran is further along in developing a nuclear weapon than experts had predicted.
After more than a decade of working behind layers of front companies and in hidden laboratories, Iran appears to be in the late stages of developing the capacity to build a nuclear bomb.
American military and intelligence officials have talked with the Pakistani government about concerns over the security of its nuclear weapons stockpile and the country's two nuclear plants, two Pakistani officials say.