It was the nightmare many had been expecting. Five years ago, hard on the heels of 9/11, someone sent anthrax spores through the US mail to journalists and politicians. Five people died, and at least 17 more got sick. The culprit was never caught.

This relatively unsophisticated attack confirmed fears, already growing in the US, that with a bit more effort a determined bioterrorist could spread disease and mayhem across the nation. To combat the threat, the Bush administration launched an unprecedented biodefence effort. To date it has spent $44 billion – three-quarters of it aimed at protecting civilians – …