Next week the United Nations nuclear Non-Proliferation Treaty (NPT) meeting in New York will be making preparations for the five-yearly review due in 2015.

The process might sound obscure, but it is important. Nuclear weapons have the power to destroy the whole planet many times over, cost vast amounts of money, consume resources that could be better spent elsewhere and, furthermore, they make war more, not less, likely.

When the NPT was first made law in the 1970s, approved by the vast majority of the member states of the UN, it had three central themes.