The United States detonated the first atomic bomb during a test in July 1945. Later that year, the U.S. used atomic bombs on the Japanese cities of Hiroshima and Nagasaki, which hastened the end of World War II. While the United States was the first nation to have nuclear weapons, nuclear proliferation did not stop with the U.S. As of late 2009, there were nine nations that currently have or are thought to have nuclear weapons and one nation, Iran, which is widely thought to be developing its own nuclear weapons program.
The Union of Soviet Socialist Republics (USSR) became the first nation after the United States to have nuclear weapons. The USSR detonated its first atomic bomb during a test in 1949. The USSR’s nuclear weapons program further intensified the growing tension between the United States and the Soviet Union and inflamed the Cold War that existed between the two nations and their allies. With the dissolution of the USSR in 1991, the former Soviet Union’s vast arsenal of nuclear weapons became the possession of the Russian Federation.
The third nation to have nuclear weapons was the United Kingdom, which tested its first atomic bomb in 1952. After the United Kingdom, the next nation to develop nuclear weapons was France in 1960, followed by the People’s Republic of China in 1964.
These first five nations are known as nuclear weapon states, meaning these are nations that are internationally recognized and authorized to have nuclear weapons and have also signed the Nuclear Non-Proliferation Treaty (NPT) of 1968. The purpose of the Non-Proliferation Treaty was to prevent nations other than the recognized nuclear weapons states from developing and possessing nuclear weapons. The NPT also encouraged the five recognized nuclear powers to pursue a policy of reducing and eventually eliminating their nuclear weapons.
There are four additional nations that are either believed to possess or confirmed to have nuclear weapons but are not members of the Non-Proliferation Treaty. India detonated its first nuclear device in 1974. India’s neighbor Pakistan followed suit and developed its own nuclear weapon in 1998.
Israel is believed to have had nuclear weapons since the 1960’s, but has neither confirmed nor denied this. The Israeli government has repeatedly stated that it would not be the first nation to introduce nuclear weapons in the Middle East region. In spite of the Israeli government’s ambiguity, ample evidence exists that seems to indicate that Israel may possess the largest nuclear arsenal outside of the five nuclear weapon states.
The People’s Republic of Korea, or North Korea, announced that it had developed a nuclear device in 2006. The government of North Korea claims to have detonated nuclear weapons in underground tests in October 2006 and in May 2009 and evidence seems to support these claims. North Korea was a signer and member nation of the Non-Proliferation Treaty but withdrew from the NPT in 2003.