two reasons for this. The first is the secrecy and evasion traditionally surrounding chemical weapons. Many possessors of chemical weapons have yet to own up. How many countries represented here believe that the three States which have acknowledged their possession of chemical weapons are the whole story? The second reason is the lack of distinctive signature for chemical- weapons-related facilities and systems. If there was such clarity, then chemical weapons would be as recognizable as, say, a tank or aircraft. We could then recognize, count, measure, weigh and in other ways assess the effectiveness, the military value of chemical weapons. But we cannot do this with confidence. We need therefore a rigorous, wide-ranging verification mechanism covering undeclared as well as declared facilities as a safety net to provide confidence in treaty compliance by signatories. An unverifiable convention would be worthless. Challenge inspection is the key to effective verification. Yet there are concerns about the implication for national security. Can challenge inspection be effective without putting at risk unrelated national secrets? I think the answer is in the affirmative. The United Kingdom approach has been to put the feasibility of challenge inspection to the test. We believe the only way to get a convincing answer is to practice the procedures in as realistic a way as possible. The detailed two-year programme of six trial inspections at United Kingdom Government-owned facilities covered some of our most sensitive security installations, including nuclear-weapons storage, nulcear-weaoons research, development and manufacture, and a sensitive communications centre. We asked ourselves the hard questions. What would be the implications for physical security? Would inspections reveal the presence and location of sensitive non-chemical weapons stores? Would they compromise information on CD/PV.564 5 (Mr. Waldegrave, United Kingdom) non-chemical weapon stock-holding, throughput and capacity? Would they qive access to classified weapon-desiqn details, especially to nuclear-weapon 
**Analysis**
The text discusses the verification mechanism for a chemical weapons convention, focusing on the challenges of detecting and counting chemical weapons facilities and systems. It also touches on the potential risks and implications of challenge inspections on national security. The text seems to be more focused on international relations, diplomacy, and security rather than economic or environmental issues.

**Category**
Science and technology, International relations