A flood of federal money has led to a building boom for high-security "hot labs," where the world's deadliest germs and potential bioterrorist weapons can be studied. The laboratories would more than triple the space to develop vaccines and treatments for anthrax, plague, hemorrhagic fevers and other killer pathogens, officials estimate.

U.S. officials say they have fresh concerns about the nation's vulnerability to terrorist attacks because they now recognize that anthrax spores could be more widely dispersed than previously believed.

To help protect against the threat of bioterrorism, the U.S. is deploying a national system of environmental monitors that is intended to tell within 24 hours whether anthrax, smallpox and other deadly germs have been released into the air.

Iraq has ordered large quantities of the drug Atropine that can be used to counter the effects of nerve gas. Officials are concerned that Iraq may be preparing to use nerve gases in conflict and are taking steps to protect their own soldiers.

President Bush signed a temporary waiver on Wednesday that permits millions of dollars to be released to programs aimed at reducing the threat posed by Russian nuclear, biological and chemical weapons.

The Bush administration has informed Moscow that Washington is curtailing many new disarmament projects because of concern about Russia's compliance with treaties banning chemical and biological weapons, according to senior administration officials.

The United States has concluded that North Korea, Iraq, Iran, Libya, and Syria are developing germ weapons, and has decided to accuse them of violating a treaty they ratified banning such weapons.

The Bush administration, reversing a course set two decades ago, has decided that the world's remaining stocks of smallpox should be retained until scientists develop new vaccines and treatments for the disease, a process that could take years if not decades.

A former senior government lawyer yesterday vigorously disputed the Bush administration's assertion that the global treaty banning biological weapons permits nations to test such arms for defensive purposes.

In a nondescript mustard-colored building that was once a military recreation hall and barbershop, the Pentagon has built a germ factory that could make enough lethal microbes to wipe out entire cities.