Landlocked and mountainous, Afghanistan has suffered from such chronic instability and conflict during its modern history that its economy and infrastructure are in ruins, and many of its people are refugees.
Since the fall of the Taliban administration in 2001, adherents of the hard-line Islamic movement have re-grouped.
It is now a resurgent force, particularly in the south and east, and the government has struggled to extend its authority beyond the capital and to forge national unity.
Its strategic position sandwiched between the Middle East, Central Asia and the Indian subcontinent along the ancient "Silk Route" means that Afghanistan has long been fought over - despite its rugged and forbidding terrain.Great Game
It was at the centre of the so-called "Great Game" in the 19th century when Imperial Russia and the British Empire in India vied for influence.
And it became a key Cold War battleground after thousands of Soviet troops intervened in 1979 to prop up a pro-communist regime, leading to a major confrontation that drew in the US and Afghanistan's neighbours.
But the outside world eventually lost interest after the withdrawal of Soviet forces, while the country's protracted civil war dragged on.
At a glance
- Afghanistan has been torn by conflict for decades
- Nato-led foreign combat troops are due to withdraw in 2014
- The Taliban - who were ousted by a US-led invasion - want to restore strict Islamic rule and have been making a comeback
Country profiles compiled by BBC Monitoring
The emergence of the Taliban - originally a group of Islamic scholars - brought at least a measure of stability after nearly two decades of conflict.
But their extreme version of Islam attracted widespread criticism.
The Taliban - drawn from the largest ethnic group, the Pashtuns - were opposed by an alliance of factions drawn mainly from Afghanistan's other communities and based in the north.
In control of about 90% of Afghanistan until late 2001, the Taliban were recognised as the legitimate government by only three countries.
They were at loggerheads with the international community over the presence on their soil of Osama bin Laden, who ordered the bombing of US embassies in Africa in 1998 and the attacks in the US on 11 September 2001.
After the Taliban's refusal to hand over Bin Laden, the US initiated aerial attacks in October 2001, paving the way for opposition groups to drive them from power and heralding a long-term, Nato-led military presence.
Predictions of the Taliban's demise after the adoption of a new constitution in 2004 proved to be premature - the extremist group came back with a vengeance and violence increased.Military withdrawal
Amid a rising death toll and the increasing unpopularity of the conflict among Western voters, pressure grew for a withdrawal of foreign forces.
In 2012, the 11th year of the conflict, Nato backed plans to hand over combat duties to Afghan forces by mid-2013. Some 130,000 Nato-led combat troops will leave Afghanistan by December 2014.
The alliance says it is committed to a long-term strategic relationship with Afghanistan beyond that date. Foreign military trainers will stay on.
Meanwhile, tentative steps towards a negotiated peace agreement began in 2012, when the Taliban announced they had agreed to open an office in Dubai for talks with US officials. Pakistan agreed to cooperate with the process after talks in Britain in early 2013, and Afghanistan said it was ready for talks in the summer.Drugs trade
Afghanistan's economy depends heavily on the drugs trade. The country supplies over 90% of the world's opium, the raw ingredient of heroin.
International bodies and governments say the drugs trade is helping to fuel the Taliban insurgency, which is estimated to receive up to US$100m a year from the trade.
The UN Office on Drugs and Crime has called on Afghanistan to target the major traffickers and corrupt government officials, who it says operate with impunity.