Nuclear warfare
After World War II, nuclear weapons were also developed by the Soviet Union (1949), the United Kingdom (1952), France (1960), and the People's Republic of China (1964), which contributed to the state of conflict and extreme tension that became known as the Cold War. In 1974, India, and in 1998, Pakistan, two countries that were openly hostile toward each other, developed nuclear weapons. Israel (1960s) and North Korea (2006) are also thought to have developed stocks of nuclear weapons, though it is not known how many. The Israeli government has never admitted or denied to having nuclear weapons, although it is known to have constructed the reactor and reprocessing plant necessary for building nuclear weapons. South Africa also manufactured several complete nuclear weapons in the 1980s, but subsequently became the first country to voluntarily destroy their domestically made weapons stocks and abandon further production (1990s). Nuclear weapons have been detonated on over 2,000 occasions for testing purposes and demonstrations.
Nuclear power by country
Nuclear power plants currently operate in 31 countries. 
Most are in Europe, North America, East Asia and South Asia.
The United States is the largest producer of nuclear power, while France has the largest share of electricity generated by nuclear power.
In 2010, before the Fukushima Daiichi nuclear disaster, it was reported that an average of about 10 nuclear reactors were expected to become operational per year, although according to the World Nuclear Association, of the 17 civilian reactors planned to become operational between 2007 and 2009, only five actually came on stream. 
Global nuclear electricity generation in 2012 was at its lowest level since 1999.
China has the fastest growing nuclear power program with 28 new reactors under construction, and a considerable number of new reactors are also being built in India, Russia and South Korea. 
At the same time, at least 100 older and smaller reactors will "most probably be closed over the next 10–15 years".