I am very pleased to have the opportunity to bring the important and urgent matter of nuclear weapons proliferation before the House. The nuclear non-proliferation treaty, or NPT, is the cornerstone of the international non-proliferation regime. The treaty came into force in 1970 and is recognised as having been a real success. It was negotiated at a time when there was a very real danger that the number of states with nuclear weapons could reach 20 or more within a decade or so. The fact that that did not happen is recognised as being in large part due to the treaty. The NPT is also given credit for the decision of a number of states that had set out on nuclear weapons programmes, or that had inherited nuclear weapons from their Soviet predecessors, to abandon that path.

The NPT is essentially a deal between those of us with nuclear weapons and those without. The non-nuclear weapons states agree not to pursue nuclear weapons. In return, they have access to civil nuclear energy and a promise of disarmament from the five recognised nuclear weapons states—China, the US, Russia, the UK and France. While the so called "grand bargain" at the heart of the NPT is easily described, supporting and enforcing it is a constantly changing task as technology advances and politics shift. The fundamental issue is whether the NPT is the way forward for the next 20 years.

The developments in nuclear proliferation have been something of a roller coaster ride in the past two decades. Following the end of the cold war, steps were taken to strengthen the non-proliferation regime, and the NPT review conferences of 1995 and 2000 gave us real grounds for optimism.

Review conferences are held every five years as part of the ongoing operation to ensure that the mechanisms in place to protect the world from nuclear proliferation are up to the job. The conferences of 1995 and 2000 were significant successes, with the conference in 2000 adopting a 13-step programme of action for the total elimination of the nuclear arsenals of the nuclear weapons states.

From 2000 onwards, however, we have been going backwards. The last review conference, in 2005, ended in failure. Nothing was achieved. Later in 2005, further efforts to strengthen the regime were made at the UN millennium summit, based on Kofi Annan's high-level panel report, "In Larger Freedom". Again, these efforts got nowhere. In the meantime, the United States and India reached a deal that significantly undermined the NPT central bargain. India is a non-NPT country, yet the US agreed to supply India with civil nuclear fuel and technology.

I am sure that other parties were content to see the lack of progress and content to let the US take the blame, but it is clear that the previous US Administration were not working to strengthen the global non-proliferation regime, to say the least. The former UK ambassador to the UN, Lord Hannay of Chiswick, has said:

"From the year 2000 onwards...the George W Bush administration applied itself quite deliberately to the de-construction of rules-based systems in the fields of arms control and disarmament."

All the while, resentment continued to grow towards the nuclear weapons states that their disarmament obligation was not being met.

The link between non-proliferation work and disarmament is strong, and is brought out in the recent report of the Foreign Affairs Committee. It is far more difficult to deal effectively with a less co-operative state, or to build support for measures to strengthen anti-proliferation work, if dissenting parties can point to the failure of the nuclear weapons states to make progress towards disarmament. At this point, I will restate my own view that the UK's decision to replace Trident is a setback.