【明報專訊】Will we ever see the end of nuclear weapons? The Treaty on the Non-Proliferation of Nuclear Weapons (commonly known as the Non-Proliferation Treaty or NPT,《核不擴散條約》), to which China became a signatory today in 1992, represents the international community's effort to achieve this goal.

1. Three components of the NPT

The NPT came into force in 1970. It has now 189 member states. The treaty contains three key components: (1) the non-proliferation of nuclear weapons, (2) the disarmament of nuclear weapons, and (3) the peaceful use of nuclear energy.

(1) The NPT recognises five "nuclear-weapon states" (NWS), namely the United States, Russia (successor state to the Soviet Union), the United Kingdom, France and China, and stipulates that they must not transfer "nuclear weapons or other nuclear explosive devices" and not in any way "assist, encourage, or induce" a non-nuclear weapon state (NNWS) to acquire nuclear weapons.

(2) Article VI of the NPT states that the signatories to the treaty "undertake to pursue negotiations in good faith on effective measures relating to cessation (停止) of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament".

(3) Article IV of the NPT acknowledges the right of all parties to develop nuclear energy for peaceful purposes in conformity with their nonproliferation obligations and to participate in exchanges of related material and information.

2. Achievements and criticisms

The NPT has been credited with bringing the number of nuclear-armed states under control. Currently there are eight sovereign states that have successfully detonated (引爆) nuclear weapons. They are the five "nuclear-weapon states" and India, Pakistan and North Korea. Israel, which maintains a policy of deliberate ambiguity (模稜兩可), is widely believed to have developed nuclear weapons. Observers believe that there would be even more nuclear-armed states had the NPT not been signed.

Several countries have voluntarily given up nuclear weapons. That has also been credited to the NPT. South Africa possessed nuclear weapons in the apartheid (種族隔離) era. It disassembled its arsenal before it joined the NPT. Former Soviet countries such as Belarus (白俄羅斯), Kazakhstan (哈薩克斯坦) and Ukraine, which inherited nuclear weapons from the USSR, eventually acceded to the NPT and returned those weapons to Russia.

There have been criticisms of the NPT, though. Some argue that it privileges the established nuclear powers over all newcomers. The treaty has also been blamed for the limited progress on nuclear disarmament. The Federation of American Scientists estimates there are more than 17,000 nuclear warheads (彈頭) in the world as of 2012. Furthermore, the NPT has failed to prevent North Korea (which withdrew from the treaty in 2003) and Iran from developing nuclear weapons.

3. Do nuclear weapons make

the world a safer place?

Nuclear weapons carry immense destructive power. The nuclear bomb dropped on Hiroshima (廣島) in 1945 towards the end of World War II directly killed around 66,000 people. By the end of that year, the death toll rose to some 140,000. Later versions of nuclear weapon are even deadlier than the Hiroshima bomb.

But there are views that nuclear weapons actually contribute to peace, as a war involving two nuclear-armed states would trigger "mutually assured destruction" (相互保證�珝�) — the complete annihilation (滅絕)of not only the defender, but also the attacker. Opponents to these views, however, argue that some people or nations may be desperate to destroy their opponents even at the cost of their own existence.