More Nukes

"The Bush administration is mounting a fresh push to add to the United States' nuclear-weapons arsenal.

In a report to go to Congress this week, the Air Force is expected to make the case for developing a "robust nuclear earth penetrator" that can destroy deeply buried targets. The earth penetrator, proposed last year by Bush-administration officials (see Nature 415, 945; 2002), would be a hardened version of an existing warhead.

The administration has also taken steps to develop new, low-yield nuclear weapons, which it says could be used to destroy chemical and biological weapon facilities. The president's 2004 budget asks for the repeal of a 1993 law that prohibits the development of weapons with yields of less than 5 kilotonnes as they would lower the threshold for using nuclear weapons."

"But scientists familiar with nuclear-weapon design questioned the usefulness of the proposal and said that it would encourage global nuclear proliferation. "'Penetrators can't penetrate very far," says Richard Garwin, a physicist who has advised the US government on nuclear-weapons policy. "And they will not destroy chemicals or even anthrax under likely conditions of storage."

Bush seeks to beef up US nuclear-weapons arsenal