Nuclear technology is a dual use technology. It may be used for the benefit of mankind in the form of energy generation or medical diagnosis and treatment. Alternatively, it may be used as a weapon of mass destruction. Ever since the discovery of atom bomb during the fag end of World War II, nuclear weapons have experienced diversification and proliferation and have posed grave threat to global peace and security. The modest use of nuclear weapons in Japanese cities of Hiroshima and Nagasaki in August 1945 by the United States during the World War II had caused severe devastation to human and material resources, which still haunts people’s memory. By now, the technological upgradation has led to steep hike in the range and scale of destructive capacity of these weapons. This is known as vertical proliferation of nuclear weapons. Along with this vertical proliferation, nuclear weapons have also experienced horizontal proliferation in last 70 years. Horizontal proliferation refers to the acquisition and development of nuclear weapon technology by new states, which hitherto did not have such technology. At the end of World War II in 1945, the United States was the only nuclear weapon state. However, by 1970 at the time of enforcement of Non-Proliferation Treaty (NPT), four other countries namely Soviet Union (Russia), China, Britain and France developed nuclear weapons and assumed the status of nuclear-weapon states (NWS). The NPT was signed in 1968 under the auspices of the United Nations, with the objective of preventing the proliferation of nuclear weapons, while at the same time permitting the use of nuclear technology for .^peaceful purposes. At present,, besides five
declared nuclear weapon states, India is a recognized nuclear weapon state and Iran, Pakistan, Israel and North Korea are the undeclared or suspected nuclear weapon states. Many countries might be on the way to acquire nuclear weapon technology in the clandestine manner.
Both vertical and horizontal proliferation of nuclear weapons and technology, along with increasing use of nuclear technology for peaceful purposes, has raised the concern for nuclear security.