Isaf aims to bring stability and long-term peace to Afghanistan
The majority of foreign troops in Afghanistan are under the command of the Nato-led International Security Assistance Force (Isaf).
Established by the UN Security Council in December 2001, its stated role is to promote security and development.
It is also involved in training the Afghan National Army (ANA) and the Afghan National Police (ANP).
As of October 2009, Isaf had 67,700 personnel from 42 different countries including the US, European countries, Australia, Jordan and New Zealand.
There are about 36,000 US troops who are not part of Isaf serving in the east of Afghanistan - on the border with Pakistan - under Operation Enduring Freedom (OEF).
Who are the main contributors to Isaf?
The launch of Isaf was Nato's first and largest ground operation outside Europe.
The largest contributing nations are the US and Britain. They provide around 31,855 and 9,000 troops respectively.
Troops from 42 countries are taken part in the Isaf operations
Isaf's mission was initially limited to Kabul, but since October 2006 its remit has expanded to all the provinces of Afghanistan.
Barack Obama, who became US president in January, pledged to send an additional 21,000 troops to Afghanistan, many of them redeployed from operations in Iraq, amid concerns about the resurgence of the Taliban.
The US and the UK have forces in Afghanistan in addition to the troops operating under Isaf command.
What is Isaf's mandate?
Isaf's stated role is to help the government of Afghanistan maintain security across the country by conducting operations in co-ordination with the Afghan army.
It also mentors and supports efforts by them to disarm illegal militias.
Nato says that the long-term aim is to help establish conditions in which Afghanistan can enjoy a stable and representative government.
It is inevitably involved in a number of military operations across the country.
Isaf is currently in charge of a major operation in Helmand aimed at breaking the Taliban's hold over the region.
Who commands Isaf and how often is the leadership rotated?
Until August 2003, command of Isaf rotated among different nations on a six-month basis. But because of difficulties in finding new lead nations, Nato took over responsibility for appointing commanders.
Since then, Isaf has been commanded by generals from Germany, Canada, Turkey, Italy, Britain and the US who have been in charge for between six months to a year.
The last three commanders have been Americans. The latest, Gen Stanley McChrystal, has made the protection of Afghan civilians the centrepiece of his new strategy.
What is the Afghan army's role?
Isaf is backed by the Afghan National Army, numbering about 94,000 in October 2009.
There are about 80,000 Afghan policemen, who are described by the British Ministry of Defence as "fully equipped and trained".
Isaf hopes to train an Afghan army of 89,500 personnel by 2011
The coalition is aiming to build and train an Afghan army of 134,000 personnel by October 2010 and to train 82,000 Afghan police officers. Isaf says 90% of its operations are now conducted in conjunction with the ANA.
What are relations like between countries contributing to and working with Isaf?
The US and senior Nato officials have appealed to Nato members to send more troops to boost combat operations in Afghanistan.
Germany, which has the third largest presence in Isaf, had been unwilling to send more troops, but pledged to increase troop numbers by about 1,000 to 4,400 this year.
But as more soldiers are killed on the Afghan battlefield, there have been fierce political debates in the UK and European countries about troop commitments as support for the war declines.
Critics have also argued that communication between Isaf and thousands of American troops - including special forces - serving with Operation Enduring Freedom (OEF) is not as strong as it should be.
They argue this is particularly the case when it comes to civilian casualties, when Isaf and OEF have been accused of issuing contradictory accounts of the number of people killed and the circumstances of the attack.
Gen Stanley McChrystal the American head of Nato forces has repeatedly said that all troops in the country must focus on protecting civilians when fighting insurgents.
Where is Isaf deployed in Afghanistan and what are its armaments?
The bulk of Isaf's forces are in the insurgency-wracked south and east of the country, especially in the provinces of Helmand and Kandahar.
Isaf's major combat teams in Afghanistan
Isaf's provincial reconstruction teams in Afghanistan
Over 40 countries contribute
forces to the international mission in Afghanistan. Full details on the
Elsewhere, Isaf troops are engaged more in peacekeeping and reconstruction than in fighting.
The division of responsibilities is the result of decisions by national governments to keep their own troops away from major combat.
This has resulted in a list of caveats which prevent their troops from being deployed in certain areas and circumstances.
Isaf has access to a wide range of weaponry from tanks and armoured personnel carriers to air support from the US and British air forces.
But military analysts say that it can be difficult to use this weaponry effectively because clashes with the Taliban tend to take place in remote and inhospitable areas where much of the fighting is at close quarters.
Is Isaf's role purely a military one?
Isaf officials often say that development without security is unachievable, and security without development is meaningless.
Isaf has construction teams to help rebuild infrastructure
It says that its mission in Afghanistan is to bring lasting peace and stability, and while that primarily involves the use of military personnel to secure the country, it also requires reconstruction and development initiatives.
It says that its activities in these fields include rebuilding damaged schools and hospitals, restoring water supplies and damaged infrastructure and supporting mediation and local governance.
In order to so, Isaf has deployed 26 Provincial Reconstruction Teams (PRTs) in different parts of the country.
What view do ordinary Afghan civilians take of Isaf?
A poll commissioned by the BBC in December 2007 across all of Afghanistan's 34 provinces revealed that most Afghans supported the presence of overseas troops, and opposed the Taleban.
Around 71% of respondents said they supported or strongly supported the presence of US military forces in Afghanistan, with 67% supporting or strongly supporting the Isaf peacekeeping mission.
Overall, the figures indicated that the peaceful north of Afghanistan was significantly more satisfied than the troubled south. Most dissatisfaction was found in the south-west, where the Taliban are most active.
The poll suggested that despite another year of conflict, confidence and hope in the future were only slightly dented.
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