Afghanistan is trying to recover from more than a quarter-century of crippling conflict, but fighting still raging in much of the country is hampering relief and reconstruction.

War, instability and isolation have left a heavily mined nation with an average life expectancy in the mid 40s and some of the highest maternal mortality rates in the world.

More than a million people died during a 10-year Soviet occupation in the 1980s and hundreds of thousands fled the country. Others left during the hardline rule of the Taliban.

U.S.-led troops ousted the Taliban in 2001 after they refused to hand over al Qaeda leader Osama bin Laden, whom the United States blames for the Sept. 11 attacks in New York and Washington.

But violence has surged since 2006 with the Taliban fighting a guerrilla war in the south and east and carrying out high-profile suicide and car bombings across the country.

The Taliban have regrouped with the help of safe havens and training grounds across the border in Pakistan and money from drug lords.

Presidential elections in 2009 - a key milestone for peace - were plagued by violence, widespread fraud and low turnout.

At the crossroads of regions and empires, Afghanistan has been subject to periodic intense foreign interest for centuries.

In 1978, a Soviet-backed communist government seized power, sparking a number of uprisings around the country as it tried to impose radical social reforms. Deteriorating security and a coup by another communist faction precipitated the Soviet invasion at the end of 1979.

Villages were bombed and thousands of civilians arrested and tortured during the occupation.

Religious fighters, or Mujahideen, covertly funded by the United States and Saudi Arabia, formed the backbone of the resistance to the occupation.

The Afghan jihad, or holy war, became a cause for Muslim warriors from around the Islamic world. The future al Qaeda leader bin Laden was among them.

The Soviets withdrew in 1989, leaving behind the communist government of President Mohammad Najibullah. Stricken by defections, Najibullah's government collapsed in 1992, and he eventually took sanctuary at a U.N. compound in Kabul, where he was hanged by Taliban forces four years later.

A Mujahideen government was established in April 1992, but it was riven with factional rivalry and the country disintegrated into civil warm during which at least 40,000 people were killed in Kabul alone.

The power vacuum allowed the Taliban, a militant student movement that grew out of hardline religious schools in Pakistan, to take the southern city of Kandahar in 1994 and Kabul in 1996.

The regime, which adhered to a strict interpretation of Islam, barred women from most activities outside the home and ruled they must wear a head-to-foot burqa in public and be accompanied by a male relative. Many women still wear the burqa.

Bin Laden and al Qaeda relocated to Afghanistan in the mid-1990s after being forced to leave Sudan. They based themselves around Kandahar.

The Taliban provoked international condemnation, particularly over their treatment of women. Only three countries - Pakistan, Saudi Arabia and the United Arab Emirates - recognised them as the legitimate government.

In 1999, the United Nations imposed sanctions to force the Taliban to turn over bin Laden, who was wanted in connection with the 1998 bombings of U.S. embassies in the Kenyan capital Nairobi and Dar-es-Salaam in Tanzania.

Throughout the Taliban's rule, fighting continued between the Taliban and the Northern Alliance. The Alliance was made up of ethnic Tajik-dominated groups who had united to fight the Taliban.

Two days before al Qaeda launched its Sept. 11, 2001 attacks on U.S. cities, a leading member of the Northern Alliance, Ahmad Shah Massoud, was killed by suicide bombers posing as journalists. Al Qaeda members were believed to have carried out the assassination to curry favour with the Taliban.

The United States launched bombing raids on Afghanistan in October 2001 after the Taliban refused to hand over bin Laden.

With U.S. help, the Northern Alliance took the northern city of Mazar-e-Sharif, then Kabul. The rest of the country swiftly followed.

At the end of 2001, members of the opposition and international organisations gathered in Germany and drew up the Bonn Agreement, which provided a political road map for Afghanistan and a timetable for reconstruction.

Hamid Karzai, a Pashtun born to the Popalzai clan, a minor sub-group of the royal Durrani tribe, was chosen to head an Interim Authority. He was later installed as president and won an outright majority in the first presidential election in 2004. Parliamentary elections were held the following year. He was reelected in 2009 after his main challenger Abdullah Abdullah pulled out, saying a planned runoff vote was not going to be free and fair.

But the government's authority remains fragile and violence has soared to the worst levels since the fall of the Taliban.

Militants have crossed the border from Pakistan to join the ranks of the Taliban fighters, who are staging increasingly sophisticated attacks, including multiple roadside bombings and complex ambushes. Taliban numbers swelled from 7,000 in 2006 to roughly 25,000 people in 2009, according to an October 2009 U.S. intelligence assessment.

The Taliban called on people to boycott the presidential elections in August 2009, and stepped up attacks to try and disrupt the poll.

U.S. President Barack Obama sent additional troops to Afghanistan in 2009, boosting the total number of foreign troops to over 100,000. Most of the new U.S. troops headed to the south, the heart of the Taliban insurgency, where British, Canadian and Dutch soldiers did not have enough strength to keep hold of ground they captured.

The majority of foreign troops operate under the NATO-led International Security Assistance Force, with soldiers from more than 40 NATO and non-NATO countries. Another 33,000 U.S. troops and some coalition forces serve on the border with Pakistan under the Unites State's Operation Enduring Freedom.

Foreign troops work with the Afghan National Army, which is about 80,000 strong and due to increase to 134,000 by 2012.

As the violence has soared, civilians have been dying in increasing numbers. More than 1,000 were killed in the first six months of 2009 - 24 percent more than the same period in 2008. Overall in 2008, over half of civilians who died were killed by Taliban insurgents and their allies, while a quarter died as a result of air strikes by U.S. and NATO-led forces.

The high number of civilian casualties has angered Karzai and weakened public support for the continued presence of foreign troops.

The Taliban insurgency has forced many schools and clinics to close, and aid agencies to restrict their humanitarian and development work at a time when drought and high food prices are putting more people under pressure.

Almost two-thirds of the country is very difficult to access, Robert Watkins, deputy U.N. envoy for Afghanistan with responsibility for development and humanitarian affairs said in September 2009.

Aid agencies are often unable to reach rural areas where the needs are greatest and security is the worst.

Increasingly, aid is channelled through Provincial Reconstruction Teams run by the armies of 14 countries, and many aid agencies use armed convoys to move around. As a result, aid workers are seen by the Taliban and other armed groups as being an extension of NATO forces and therefore legitimate targets. Dozens of aid workers have been injured, kidnapped or killed.

The Taliban's fall triggered one of the largest and swiftest refugee repatriations in the world.

Millions of Afghans fled to neighbouring countries during the years of conflict.

Since 2002, Afghans have been streaming home, mostly from Iran and Pakistan. As of July 2009, more than 5 million Afghans had returned to their country, according to the U.N. refugee agency (UNHCR). But 2.6 million are still in Pakistan and Iran and many others are further afield. For detailed figures, check UNHCR's Afghan refugee statistics.

The rate of return has steadily dropped, partly because of the rise in violence. Some people have started going abroad again while others have fled to safer parts of the country. Drought, poverty and lack of job opportunities have also forced many to seek employment elsewhere.

But neighbouring countries are tiring of the large numbers of refugees. Pakistan has said it wants the remaining Afghans on its soil to go home, and Iran has deported some Afghans.

UNHCR figures say 235,000 were internally displaced in June 2009.

Both internally displaced people and refugees face "re-displacement" upon their return home, either because of the lack of economic opportunities or because of unresolved land and property disputes or because their homes are now battle zones. Rural areas are increasingly insecure, forcing many returning Afghans to migrate to towns and cities.

Many also face the risk of landmines and unexploded ordnance left over from the war. Hundreds of people are killed or injured each year, according to the Mine Action Programme for Afghanistan. About half the victims are children.

The contamination poses a formidable challenge to social and economic reconstruction, which is critical to the country's political stabilisation. Demining organisations hope the country will be free of mines by 2013.

Billions of aid dollars have poured into Afghanistan to help rebuild the shattered infrastructure and economy. Afghanistan depends on aid for 90 percent of its spending. But international donors have fallen behind in paying what they have already pledged, partly because of concerns about corruption.

Donors have committed to spend some $25 billion on reconstruction and development since 2001, but by March 2008, just $15 billion in aid had been spent, according to the Agency Coordinating Body for Afghan Relief (ACBAR), an alliance of aid agencies. An estimated 40 percent of this was returned to donor countries in corporate profits and consultant salaries, says ACBAR.

Local government institutions lack skilled staff and expertise, and only half of the country's district governors have an office building. ACBAR says too many aid projects are designed to deliver rapid visible results rather than build capacity and ensure sustainable long-term poverty reduction that would reduce Afghanistan's dependence on foreign help.

"Most aid has been directed to Kabul or other urban centres, rather than to rural areas where it is most needed and more than three-quarters of Afghans live," says the report.

Spending on aid by all donors since 2001 amounts to around $7 million a day, says the ACBAR report. By contrast, the U.S. military spends some $100 million a day fighting Taliban insurgents.

The United Nations launched a $4 billion development plan in October 2009, to run from 2010 to 2013. This United Nations Development Assistance Framework covers governance, peace, agriculture, food security, health, education, water and sanitation.

U.N. agencies and non-governmental organisations have set up shop throughout the country, but the violence is escalating and is a major obstacle to delivering aid.

"Afghans consistently rank insecurity as their top concern," says Human Rights Watch. "Resurgent Taliban forces have managed to contest the government's control over much of the southern part of the country, curtailing the delivery of desperately needed development and reconstruction assistance.

"In other areas, warlords are further entrenched and have even been elected to and placed their supporters in parliament," it adds.

Experts blame the surge in violence on a weak central government, banditry, a booming narcotics trade and the insurgency. Distinguishing between and dealing with the different actors can be hard, they say.

Reconstruction efforts have been dogged by allegations of corruption and waste on the part of the government, aid agencies and contractors.

Government officials and international aid workers have been accused of stealing money or taking bribes. Some companies that won contracts to rebuild the country have been accused of leaving behind them shoddy roads, hospitals and schools or even nothing at all.

Donors spend most aid money outside state channels to avoid it being siphoned off by corrupt officials. But they are doing so without telling the Afghan government how and where the funds are being spent. Critics say this undermines the government's authority, and complicates planning and coordination between donors and provinces.

Lorenzo Delesgues, director of Integrity Watch Afghanistan, a local independent watchdog, says real and suspected waste and misspending are turning parts of the Afghan population against aid workers.

"There are millions spent here and a lot of people feel that it is not reaching the right people," he said.

"The impact (of corruption) is that it puts everything in the same bag ... so that all the money spent in Afghanistan risks losing its credibility. Afghans see foreigners in expensive cars, with big salaries ... people feel they are not spending this money correctly," Delesgues added.

The international Afghanistan Compact, a five-year plan launched by donors and the Afghan government in 2006, aims to combat corruption and ensure transparency, as well as security issues, human rights and economic and social development.

Public sector corruption has steadily worsened, and in 2009 Afghanistan was ranked the second most corrupt country in the world, after Somalia by Transparency International's Corruption Perceptions Index.

Violence is not the only threat to life. Children born in Afghanistan face myriad obstacles that can prevent them from reaching adulthood - the country's child mortality rates are among the highest in the world, with nearly 20 percent dying before their fifth birthday, according to U.N. children's agency UNICEF.

Diarrhoea, respiratory infections, malaria and malnutrition are the biggest killers. The majority of the population lacks access to safe drinking water and sanitary facilities. Afghanistan is one of four "polio endemic" countries, according to the World Health Organisation (WHO).

Tuberculosis is another major public health challenge. Experts say women in particular suffer high rates because they tend to spend most of their time indoors and have less access to medical care than men do.

Maternal mortality rates in Afghanistan are the second highest in the world. In the southern region, nearly 50 women a day die from complications in pregnancy and childbirth says UNICEF.

A new health problem emerged in 2006 in the form of the H5N1 bird flu virus, which has been found in several provinces.

The U.N. Food and Agriculture Organisation has warned that dealing with bird flu could be particularly difficult for Afghanistan, as its public veterinary services are weak. About 85 percent of the population lives in close contact with poultry.

Afghanistan produces over 90 percent of the world's heroin, says the United Nations. The Taliban, which banned cultivation during their rule, are exploiting the trade to fund their insurgency. The majority of poppy fields are in the country's south and southwest where the Taliban are most active.

The U.N. Office on Drugs and Crime (UNODC) says the potential export value of Afghan opiates stood at about $3.4 billion in 2008. The Taliban earn on average $90-160 million a year from opiate farming and trade in Afghanistan alone, says UNODC. Experts say the Taliban also benefit from a $1 billion opiate trade in Pakistan.

Eradication efforts have infuriated farmers who say they would be destitute without their crops. Many farmers depend on loans provided by drug traders as a down payment for the subsequent drug harvest.

U.S. special envoy to Afghanistan Richard Holbrooke said attempts to destroy crops had been ineffective. They penalised the farmers and had no impact on the Taliban's earnings from the trade - rather it helped them recruit. In June 2009, he said the programme would be phased out.

One of the main tools in combating the narcotics trade involves fostering alternative livelihoods. The idea is to wean farmers away from poppy cultivation by offering them fertilisers and seeds for legal crops.

Poppy cultivation has dropped since peaking in 2007, especially in the north.

Drugs don't just affect those beyond Afghanistan's borders - there are close to one million addicts in the country, according to UNODC. Drug use is high among refugees returning from Iran and Pakistan.

Life for women and girls has improved in some parts of the country since the Taliban was toppled.

During the Taliban years, the regime prohibited women from attending universities and shut girls' schools in Kabul and other cities, although primary schooling did go on in many other areas of the country. Earning a living was also very difficult, a tragedy in a country with tens of thousands of war widows - in Kabul alone there are estimated to be up to 50,000.

Today, women have the right to vote - 68 were elected to parliament in 2005. Millions of girls go to school and women are allowed to work outside the home.

But the daily life of many women is still dominated by the threat of violence and backbreaking toil.

Many girls are married off as children or young teenagers, and the vast majority never learn to read or write.

Afghanistan also has one of the highest rates of maternal mortality in the world.

Human Rights Watch says violence against women and girls remains rampant, including domestic violence, sexual violence, and forced marriage.

In many cases women who are raped are charged with immorality and imprisoned. They can also be jailed for the crime of running away from their husband.