An international rapid-reaction unit to investigate bioweapons incidents is being discussed this week at a meeting in Geneva of the parties to the Biological Weapons Convention (BWC).

The treaty, which has been in force since 1975, outlaws states from developing, stockpiling or using biological weapons. But efforts to give it a mechanism for checking whether states comply with its terms were blocked by the United States in 2001 (see Nature 414, 675; 2001) and are still in limbo.

With no broad verification scheme expected any time soon, supporters of tougher checks are trying to promote less ambitious alternatives. The proposed rapid-reaction unit, for example, which is being championed by Britain, would be limited to fact-finding missions after an alleged bioweapons incident had taken place. It would have no powers to investigate allegations that a state or plant was manufacturing bioweapons.

A rapid-response unit would at least give the BWC some teeth, its advocates say, and planning for it will force the treaty's 152 parties to discuss technical and other issues relevant to wider verification procedures. This would include drafting lists of experts, equipment and transport, as well as agreements on procedures for handling samples and carrying out laboratory tests.

Angela Woodward, a disarmament specialist at the non-profit Verification Research, Training and Information Centre based in London, points out that Kofi Annan, the director-general of the United Nations (UN), already has powers to call for investigations of alleged chemical or bioweapons uses under a 1989 UN law.

The law was developed with chemical weapons in mind, and has become largely redundant since the Chemical Weapons Convention was equipped with its own verification procedures in 1997. But it could be resuscitated relatively simply, Woodward says, and adapted for bioweapons fact-finding missions.

A working paper drafted by UK experts agrees that the law has not “been reviewed or updated” since 1989. “It is therefore now time to re-establish an effective United Nations procedure for investigating allegations of biological weapons use or suspicious outbreaks of disease,” the paper says. It argues that the BWC could guide an update of the law to take account of the specific needs of a rapid-response unit.

This week's meeting is one of three annual summits intended to keep discussion on bioweapons alive before the next major negotiations on the BWC in 2006. It will discuss the rapid-response proposal but will not take a decision on whether to implement it. Advocates hope, however, that the meeting will pave the way for putting the proposal on the agenda at the UN general assembly next year.