Weapons of mass destruction (WMD) generally include nuclear, biological, chemical weapons. The term first arose in 1937 in reference to the mass destruction of Guernica, Spain, by aerial bombardment that was made by the German Luftwaffe during the Spanish Civil War.
Nuclear weapons did not exist at that time, but biological weapons were being researched by Japan and chemical weapons had seen wide use. Following the bombing of Hiroshima and Nagiasaki, and progressing through the Cold War, the term came to refer more to non-conventional weapons: atomic, biological and chemical weapons.
The phrase entered popular usage in relation to the U. S.-led multinational forces 2003 invasion of Iraq and today the most widely used definition is that of nuclear, biological or chemical weapons.
The development and use of WMD is governed by international conventions and treaties, although not all countries have signed and ratified them. There are 8 countries that are known to possess
nuclear weapons and, of course, other WMD, only 5 of which are members of the NPT (Nuclear Non-Prolif eration Treaty). All states which possess WMD can be divided into four main groups.
The first one is the group of states which are commonly accepted to possess nuclear weapons: China: France; India; Israel; Pakistan; Russia; the United Kingdom; and the United States of America.
The second one is the group of states with access to nuclear weapons through nuclear sharing agreements: Belgium, Germany, Italy, the Netherlands and Turkey.
The third is the group of states currently suspected of possessing or developing nuclear weapon capabilities. They are Iran and North Korea.
And the last group of countries is states that formerly possessed nuclear capabilities: South Africa, as well as Belarus, Kazakhstan, and Ukraine following the break-up of the former Soviet Union.
Weapons of mass destruction, especially nuclear weapons are rarely used because their us^is essentially an “invitation” for a WMD retaliation, which in turn could escalate into a war so destructive it could easily destroy huge segments of the world’s population. During the Cold War, this understanding became known as mutually assured destruction and was largely the reason war never broke out between the WMD-armed United States and Soviet Union.
But nowadays there is a great concern that the weapon of this kind can be available for terrorist organizations, moreover can be used by these organizations.