History of nuclear weapons

[Waseemtabish]

The first nuclear weapons were created in the United States, by an international team including many displaced émigré scientists from central Europe with assistance from the United Kingdom and Canada, during World War II as part of the top-secret Manhattan Project. While the first weapons were developed primarily out of fear that Nazi Germany would develop them first, they were eventually used against the Japanese cities of Hiroshima and Nagasaki in August 1945. The Soviet Union developed and tested their first nuclear weapon in 1949, based partially on information obtained from Soviet espionage in the United States. Both the U.S. and USSR would go on to develop weapons powered by nuclear fusion (hydrogen bombs) by the mid-1950s. With the invention of reliable rocketry during the 1960s, it became possible for nuclear weapons to be delivered anywhere in the world on a very short notice, and the two Cold War superpowers adopted a strategy of deterrence to maintain a shaky peace.Nuclear weapons were symbols of military and national power, and nuclear testing was often used both to test new designs as well as to send political messages. Other nations also developed nuclear weapons during this time, including the United Kingdom, France, and China. These five members of the "nuclear club" agreed to attempt to limit the spread of nuclear proliferation to other nations, though at least three other countries (India, South Africa, Pakistan, and most likely Israel) developed nuclear arms during this time. At the end of the Cold War in the early 1990s, the Russian Federation inherited the weapons of the former USSR, and along with the U.S., pledged to reduce their stockpile for increased international safety. Nuclear proliferation has continued, though, with Pakistan testing their first weapons in 1998, and North Korea performing a test in 2006. In January 2005, Pakistani metallurgist Abdul Qadeer Khan confessed to selling nuclear technology and information of nuclear weapons to Iran, Libya, and North Korea in a massive, international proliferation ring. On October 9, 2006, North Korea claimed it had conducted an underground nuclear test, though the very small apparent yield of the blast has led many to conclude that it was not fully successful (see 2006 North Korean nuclear test).
Nuclear weapons have been at the heart of many national and international political disputes and have played a major part in popular culture since their dramatic public debut in the 1940s and have usually symbolized the ultimate ability of mankind to utilize the strength of nature for destruction.
There have been (at least) four major false alarms, the most recent in 1995, that almost resulted in the U.S. or USSR/Russia launching its weapons in retaliation for a supposed attack.Additionally, during the Cold War the U.S. and USSR came close to nuclear warfare several times, most notably during the Cuban Missile Crisis. As of 2005, there are estimated to be at least 29,000 nuclear weapons held by at least eight countries, 96 percent of them in the possession of the United States and Russia.