Sir

Your article on the controversy surrounding destruction of the smallpox virus presented well the difficult and complicated issues facing international policy-makers (Nature 398, 741; 1999). But one statement attributed to me was seriously in error. It is alleged that I said that the US Department of Defense wished to see stocks of variola virus retained in order to retaliate in kind should the United States be subjected to a bioweapons attack. From this, it might be implied that the United States was not intent on meeting the obligations of the Biological Weapons Convention that ban offensive weapons. That would be a serious matter indeed.

The US stock of offensive weapons was destroyed more than 20 years ago. During my years of government service, I know of no one who ever suggested using biological weapons in retaliation or in any other manner. One would hope that this might one day be the accepted norm for all countries.