The United States of America made experiments and then developed its first nuclear weapon in second World War with the help of UK and Canada. They developed it in fear of Nazi Germany in order to take control over them. USA tested its first nuclear attempt on 16th of July 1945. USA then became the first country to hold nuclear power and then they also used these nuclear bombs on Hiroshima and Nagasaki, causing destruction in return.They also worked on hydrogen bomb and tested it on 1952.
2 – Russia
Russia, which was known as Soviet Union earlier, they made their first nuclear weapon after USA in 1949. This happened during and after the second world war, they did several attempts and become successful second nation to have a nuclear power. This was done to achieve a balance in power during war. They followed USA and also tested for hydrogen bomb and announced it in 1955. They also made powerful weapon at that time hich is considered as 100 megatons of nuclear power.
3 – United Kingdom
The third country that become a nuclear state after Russia is United Kingdom.They done their tests on 1952. The take help from different nations for this purpose. Austria, Germany and France helped UK universities to do research for making nuclear weapons a reality. UK also teamed up with their partners like USA and Canada during this project. At the end they developed their own research and manufactured bombs like USA. The developed their war heads to coupe up and be prepared against Soviet Union and to keep their status as nuclear power. They also tested hydrogen bomb during 1957.
4 – France
France had issues with Soviet Union and its allies like UK, USA. This made their interest to develop nuclear weapons. France did its own research and conducted their nuclear tests in 1960. This made possible for them to have powers and maintain balance of power with UK during cold war. France didn’t stop there, they also tested hydrogen bomb during 1968. France kept on working and research for modernization of its war heads. They developed submarine based ballistic missiles and other war heads with capability to carry nuclear weapons.
5 – China
China worked hard to achieve their goals to become nuclear state. They were working to be deterrent against two nuclear powers USA and Soviet Union.Chain tests its first nuclear device in 1964. After just few years they were also able to develop missiles carrying nuclear bombs. China also tested their hydrogen bomb in 1967 just after three years from becoming nuclear state.
6 – India
India secretly made nuclear weapons when other nations like Canada have supplied them nuclear reactors for electricity generation purpose. This caused dispute with other nations as India didn’t informed their plan of making nuclear weapons. India tested its nuclear weapon in 1974 and called it “peaceful nuclear explosive”.India didn’t allow international powers to control of their nuclear facilities.They weaponized their nuclear weapons for missile launches in 1998.
7 – Pakistan
Pakistan also secretly developed its nuclear weapons during years, beginning in the late 1970s. It was considered that Pakistan has nuclear weapons from the 1980s but USA didn’t accepted it. Sanctions were imposed on Pakistan to restrict its aid from USA, in order to make Pakistan agreed on disarming from nuclear facilities. But Pakistan kept its research and conducted nuclear tests. They tested 6 tests on 1998 in comparison with India as they conducted 5 testes before.
8 – North Korea
North Korea was a party of Treaty but then it withdraws from it in 2003 because USA suspects that North Korea has secretly developed uranium programs and put sanctions on them. In 2005 North Korea claimed that they have nuclear weapons but not tested yet.The world didn’t believed them at that time but in 2006 North Korea warned USA that they would conduct nuclear test to confirm the world about their nuclear assets. North Korea tested a successful nuclear test on 2006 and again tested second time in 2009. They also done a third test in 2013 to make realize outer world about the presence of nuclear weapons.
9 – Israel
Israel is also considered to hide its nuclear assets for a long time as they are sixth in row of nuclear armed countries but kept their program secret from outer world. It is considered that Israel has nuclear facilities from as earlier as 1966. Israel was not a part of Treaty and justify their research as Israel is not the the first country to develop nuclear weapons in world.
10 – Iran
In 1970, Iran withdraw from treaty to develop nuclear programs. Nuclear program of Iran includes research sites, uranium mines and reactors. Iran’s nuclear program was actually launched during 1950s with the help of the USA. USA and other nations participated with Iran until 1979.After Iranian revolution international nuclear deals with Iran were abandoned. After 1990s Iran negotiated with France and Argentina.They were then agreed on a joint research in the field of nuclear development.Iran says its nuclear program is peaceful, but USA always demanded its nuclear facilities detail and activities. USA has imposed many allegations and sanctions on Iran.