Nuclear weapons had played a vital role during the cold war. When the cold war had ended in late 1980s and the early 1990s, there was a sense of relief as a great threat to the world was over. However, right after that, the idea that the possession of nuclear weapons by some country might lead to the spread of nuclear technology in the world did worry people. People believed that this might lead to great destruction and harm to world if the usage became common, thus, making the world a dangerous place to live in. (Sir Laurence Martin)
Defense - Almost every nation in today's world is under threat by one or the other nation for various reasons, example; political, resources, history and religion. Every civilian needs the head of state to take responsibility of their security and to let peace prevail. State security requires a good military force and arsenal, so that if it is attacked by a rival state, they can fight back and protect their nation and people. Nuclear weapon is although dangerous, but it is a very strong type of weaponry which gives a sense of security that fighting back will not be a problem at all.
Prestige - In the post cold war world, only very strong nations such as the UK, USA, France, Russia and China possess nuclear weapons. ...