What it is: During the Cold War this expression was used to refer to nuclear weapons. In the 1990s chemical and biological weapons (CBW) were added. The US defines these as 'any weapon or device that is intended, or has the capability, to cause death or serious bodily injury to a significant number of people through the release, dissemination, or impact of toxic or poisonous chemicals, a disease organism, or radiation or radioactivity'.

 - placard at anti iraq war demonstration

What it means:
Nuclear weapons. The only two nuclear bombs ever used were dropped by the USA on Japan in 1945. Each devastated a city and its population. Today at least 8 states, including the USA and the UK, owned nuclear warheads of much greater power. Nuclear weapons can destroy very large areas, leaving a radioactive wasteland.

(2) Chemical weapons. These include gases that burn, choke or poison, and 'nerve agents' which attack the nervous system and cause paralysis and death. Despite an international ban in 1925, chemical weapons have been used a number of times and many thousands of people have been killed. A new and tougher Chemical Weapons Convention (CWC) came into force in 1997. States signing the treaty (158 by the end of 2003) agree not to develop, produce, acquire, stockpile, pass on, or use chemical weapons. In 1997 the international Organisation for the Prohibition of Chemical Weapons (OPCW) was set up to monitor and oversee the dismantling of existing chemical weapons arsenals - and investigate any reports that the CWC wasn't being observed. Chemical weapons affect a much smaller area than nuclear weapons. Though they have mainly been used against people they are also manufactured to destroy trees (as Agent Orange did in Vietnam) and  crops. These defoliant sprays cause harm to the people who come into contact with them; Vietnamese children are still being born with serious disabilities. 

(3) Biological weapons. These are armed with living viruses and bacteria, or poisons obtained from living organisms, to spread fatal diseases. The Biological Weapons Convention (BWC), which came into force in 1975, bans the research, development, production, stockpiling or acquisition of such weapons (and systems designed to deliver them). 155 states had signed and ratified the BWC todate (2006). Biological weapons are aimed deliberately at people and their environments. Their potential scope is vast: the spread of human viral diseases (or diseases of, say, plants which humans eat) could wipe out whole populations. And you only need a small quantity of biological agents (unlike chemical ones) to kill many thousands. This is why weapons like these are associated in people's minds with terrorism.

Think about it:
Consider the problems of controlling WMD. For example, civilian nuclear power processes can be adapted to make material for nuclear weapons. Biotechnology and pharmaceutical firms can sell material that might be misused. Chemicals for legitimate purposes (fertiliser, say) can be combined with others in secret to make a deadly mixture. Laboratories making CBW can be disguised and concealed (often as 'research'). As for exports, even when licences are granted for 'innocent' materials, there's still no control over what the materials might ultimately be used for, or where, or by whom. Maybe 'controls' can never work. Maybe it's a question of dealing with the reasons why terrorists or states want these weapons at all?

(2) The BWC has no organisation like the OPCW to monitor it. Here's what an administrator of the International Committee of the Red Cross (ICRC) says: 'Waging war has so far been a generally military business, and that's horrific enough. But the hostile release of biological agents to destroy agriculture, alter the behaviour of people, or change the human gene pool would probably be far worse. The greatest threat to the future may be from people in academic, industrial or military laboratories, ignoring or disregarding what the agents they're working on could be used for in the wrong hands. The failure of governments to agree on a monitoring regime for the BWC should be enough to keep people awake at night.' So why aren't there vigorous grass-roots campaigns for an OPBW?

(3) The concept of 'Weapons of mass destruction' has become destructive itself. The words are an expression of undefined menace. Leaders of states owning WMD have given 'possession of WMD' as a reason for attacking other states suspected (not always on reliable evidence) of owning WMD. How might this peculiar logic be shown up for the flawed (and dangerous) thinking it is?

| nuclear weapons | chemical weapons | biological weapons |