Hamid Karzai has been seeking a second term as Afghan president
President Hamid Karzai has been declared Afghanistan's elected president for a second term after a vote mired in controversy.
Widespread fraud in the 20 August first round led to Mr Karzai being stripped of the outright win he appeared to have secured.
A second round run-off scheduled for 7 November was called off after Mr Karzai's sole remaining challenger, Dr Abdullah Abdullah, pulled out saying the vote could not be free and fair.
Should a second round have been held?
This is as much a practical as a constitutional question.
Some critics argue that it is simply illegal to abandon a run-off which election law says has to be held if no candidate achieves more than 50% of the popular vote.
But when Dr Abdullah pulled out of the run-off, there would only have been one name on the ballot paper.
All seven members of Afghanistan's Independent Election Commission (IEC) are said to have considered the options according to the law. Many analysts argue that the constitution is genuinely ambiguous.
And Dr Abdullah's withdrawal from the race was an unforeseen development.
But a number of MPs and other observers argue that Mr Karzai has not been elected by a majority of voters - and they say without a second round the legitimacy of his government is bound to be compromised.
Nevertheless correspondents say there was mounting pressure on election organisers to abandon plans because of practical considerations.
Western governments were privately reluctant to risk the lives of troops and voters to secure a second round when the result was already a foregone conclusion.
Who was favourite to win a run-off?
Mr Karzai is from Afghanistan's majority Pashtun community and was the favourite.
Abdullah Abdullah says hundreds of ballot boxes were stuffed
Dr Abdullah is a Tajik-Pashtun but lacks his own power base within the Northern Alliance, which dominated the government formed after the ousting of the Taliban in 2001.
Following the first round fraud probe, Mr Karzai saw his share of the vote drop to 49.67% - below the crucial 50% plus one ballot threshold needed to avoid a second round.
Dr Abdullah was adjudged in the end to have won about 31% of valid votes cast.
What happens now?
There is not going to be a radical shift in Afghanistan's power structure for the moment.
But there are still many questions hanging over the muddled sequence of events that led to the decision to abandon the run-off and that could affect events in the next few weeks and months.
Many political commentators still say that the election commission's decision was simply unconstitutional. Theoretically, there is room for it to be challenged.
The Afghan election commission itself is subject to controversy - its commissioners were all appointed by Mr Karzai and many allege it has not acted independently or impartially.
Mr Karzai was an increasingly unpopular figure and many critics are questioning how he can effectively govern.
An effective administration is central to US President Barack Obama's strategy in Afghanistan. The US needs a credible partner there at time when it is considering another major deployment of troops.
The question of how to create a legitimate and credible government is likely to be top of Mr Karzai's agenda.
He may only provide an answer to his critics once he reveals the ethnic and political make-up of his new cabinet.
How likely is a power-sharing deal?
Correspondents say it is still possible that President Karzai and Dr Abdullah may reach an agreement to form a national unity government.
There has been enormous diplomatic pressure in recent days, with some of it apparently aimed at securing a deal.
Mr Karzai has said "there is no place for a coalition government in the law".
But in his first speech after being declared the victor he promised an inclusive government and said it was open to anyone who wanted to work with him - whether they supported or opposed him.
Early in the election process, Dr Abdullah ruled out negotiations but later appeared to soften his stance.
His subsequent withdrawal from the race has only increased speculation about a backroom deal.
Whether or not he or his followers have a place in a future Afghan cabinet and government may be key to how the administration is viewed - both by Afghans and the international community.
How has the row affected Western policy?
The stalled results of Afghanistan's elections have led to paralysis within the international community over key decision-making about Afghanistan.
Afghanistan is a major strand of President Obama's foreign policy. But the White House has said that it will not take a decision on whether or not to send more troops to Afghanistan until a new government has been formed.
The delay comes at a time when Nato and US commanders have warned that the next six to 12 months will be critical in determining whether the mission in Afghanistan succeeds or fails.
How bad was the fraud?
After receiving more than 2,000 complaints of fraud and intimidation, the Electoral Complaints Commission (ECC) "quarantined" results from 600 stations where there were suspected irregularities.
On 10 September it announced for the first time it was invalidating some ballots. The ECC then ordered an audit and recount of stations where turnout was at or above 100%, or where one candidate won more than 95% of the vote.
On 19 October the panel deducted hundreds of thousands of votes from the main candidates. Its investigation focused on 600 of the most serious complaints, and a sample audit of suspect votes at 3,377 polling stations. At 210 polling stations all the ballots were invalidated.
Election officials say that Mr Karzai's vote share dropped to 49.67%, Mr Abdullah's to 30.59 %.
Some 1.3 million votes for Mr Karzai were invalid, about a quarter of the total cast, the group added.
Correspondents say before the announcement of a second round, the Afghan leader believed victory had been stolen from him. His opponent said the fraud was "state-engineered".
Mr Karzai had refused to sack the head of the IEC - a key condition of Dr Abdullah for standing in the second round.
How does the election system work?
The president of Afghanistan is elected for a five-year term and can serve a maximum of two terms.
In order to win the election, a presidential candidate must receive more than 50% of the votes cast.
If no-one receives this, a run-off should be held within two weeks of the announcement of the results.
Presidential candidates must hold Afghan citizenship and be born of Afghan parents. They are not allowed to hold any other nationality. They must also be Muslims and be at least 40 years old.
What about the voters?
There are 17 million out of an estimated 30 million Afghans registered to vote. The minimum voting age is 18.
There were separate voting areas for men and women during the poll
Afghan refugees in Pakistan and Iran did not take part in the election.
There were approximately 7,000 polling centres and more than 25,000 polling stations across Afghanistan, with separate areas for men and women.
The logistics of setting up polling stations in a country with poor security, rugged terrain and a lack of infrastructure prompted a senior UN official to describe the poll as the most complicated election he has seen.
Almost all the problem centres are in the country's ethnic Pashtun areas, where the insurgency is at its strongest. In many of those areas, it was too dangerous to send monitors to oversee the vote.