Iran says its nuclear regime is peaceful
Iran announced on 15 November that it will suspend the enrichment of uranium as requested by the UN nuclear agency the International Atomic Energy Agency (IAEA).
Why is the issue of enrichment so important?
Under the Nuclear Non-Proliferation Treaty, a country is allowed, under inspection by the IAEA, to enrich uranium to a level needed for nuclear power. Most however do not and get fuel from others. The problem is that the same technology can also be used to enrich uranium for nuclear weapons.
There are fears that Iran might do this as well, either in secret or by developing the technology and then withdrawing from the treaty to make a bomb openly.
If it is legal to enrich uranium for fuel, why should Iran be asked not to do so?
Iran was not asked to abandon enrichment by the IAEA - though many countries, including the US and Britain, say that it should be, on the grounds that it cannot be trusted.
It was asked simply to suspend its programme as a sign of good faith while more rigorous inspection methods, known as an Additional Protocol, are implemented. Iran has yet to ratify its acceptance of this protocol, which it has accepted in principle.
The IAEA lost confidence in Iran because Tehran hid an enrichment programme for many years.
Why has Iran now agreed?
Iran initially rejected the demand for suspension, saying that it would "not accept any obligation regarding the suspension of uranium enrichment".
However, in talks with three European countries -- Britain, France and Germany - it was offered trade concessions and help with fuel for its nuclear reactor if it at least suspended enrichment. Further talks are due in December.
It is also and perhaps more importantly likely that Iran wanted to avoid being reported to the Security Council where it could face sanctions for having broken IAEA rules in the past.
The IAEA is meeting on 25 November to consider these issues.
Does Iran intend to build nuclear weapons?
It says not but few believe it. Others argue that it has no need to make its own nuclear fuel as this can be provided by others, so that it must be intending one day to make a bomb. Iran says that it cannot rely on outside sources for fuel.
One possibility is that Iran wants to develop the capability but has left a decision on whether actually to build a nuclear weapon for the future.
Might the US or Israel bomb Iran if there is no solution?
The US has said publicly that it will not permit Iran to develop nuclear weapons. Israel has started a diplomatic campaign to publicise its view that Iran intends to do so.
The US has not threatened the use of force but air strikes of the kind Israel carried out to bomb Iraq's nuclear reactor in 1981 cannot be ruled out, though these would not be easy.
What is the Nuclear Non-Proliferation Treaty?
The NPT was an agreement opened for signature in 1968 under which those countries with nuclear weapons at the time (the US, Russia, China, Britain and France) were allowed to keep them but agreed not to give them to anyone else.
However, other countries are allowed to develop nuclear power for peaceful purposes under the inspection of the IAEA. If they make the fuel themselves it has to be under strict inspection.
The nuclear weapons countries also promised to work towards nuclear disarmament, but this has not really happened.
And several nuclear-weapons capable states - Israel, India and Pakistan - have not signed up to the treaty so they can develop weapons. Another, North Korea, has withdrawn from it.