Afghanistan, officially the Islamic Republic of Afghanistan, is a landlocked country at the crossroads of Central and South Asia. Afghanistan is bordered by Pakistan to the east and south; Iran to the west; Turkmenistan, Uzbekistan, and Tajikistan to the north; and China to the northeast. Occupying, it is a mountainous country with plains in the north and southwest. Kabul is the capital and largest city. The population is around 32 million, mostly composed of ethnic Pashtuns, Tajiks, Hazaras, and Uzbeks.
Settled life emerged in present-day Afghanistan and adjoining areas 9,000 years ago, evolving gradually into the Indus Valley Civilization of the third millennium BCE. Indus civilization's archaeological sites were discovered on the Amu Darya at Shortugai and in Kandahar Province at Mundigak; the latter flourished during the Bronze Age Helmand culture. Indo-Aryans migrated through Bactria-Margiana area to Gandhara, followed by the rise of the Iron Age Yaz I culture, which has been closely associated with the culture depicted in the Avesta, the ancient religious texts of Zoroastrianism. The region, then known as "Ariana", fell to Achaemenid Persians in the 6th century BCE, followed by Alexander the Great in the 4th century BCE, who married Roxana in Bactria before his Kabul Valley campaign, where he faced resistance from Aspasioi and Assakan tribes. The Greco-Bactrian Kingdom became the eastern end of the Hellenistic world. Following the conquest by Mauryan Indians, Buddhism and Hinduism flourished in the region for centuries. The Kushan emperor Kanishka, who ruled from his twin capitals of Kapiśi and Puruṣapura, played an important role in the spread of Mahayana Buddhism to China and Central Asia. Various other Buddhist and Hindu dynasties also ruled the region, including the Saka, Kidarite, Hephthalite, Alkhon, Nezak, Zunbil, Turk Shahi, and Hindu Shahi.
Muslims brought Islam to Sassanian-held Herat and Zaranj in the mid-7th century, while fuller Islamization was achieved between the 9th and 12th centuries under the Saffarid, Samanid, Ghaznavid, and Ghurid dynasties. In the 13th century, the Khwarazmian-held region was ravaged by Mongols. Parts of the region were later ruled by the Khalji, Timurid, Lodi, Sur, Mughal, and Safavid empires. The political history of the modern state of Afghanistan began with the Hotak dynasty, whose founder Mirwais Hotak declared southern Afghanistan independent in 1709. In 1747, Ahmad Shah Durrani, who is considered as the founder of the state, established the Durrani Empire with its capital at Kandahar. In 1776, the Durrani capital was moved to Kabul while Peshawar became the winter capital; the latter was lost to Sikhs in 1823 followed by an unsuccessful attempt to recover it in 1837. In the late 19th century, Afghanistan became a buffer state in the "Great Game" between British India and the Russian Empire. In the First Anglo-Afghan War, the British East India Company seized control of Afghanistan briefly, but following the Third Anglo-Afghan War in 1919 the country was free of foreign influence, eventually becoming a monarchy under Amanullah Khan, until almost 50 years later when Zahir Shah was overthrown and a republic was established. In 1978, after a second coup, Afghanistan first became a socialist state and then a Soviet protectorate, evoking the Soviet–Afghan War in the 1980s against mujahideen rebels. By 1996, most of the country was captured by the Islamic fundamentalist Taliban, who ruled as a totalitarian regime for over five years; they were removed from power after the US invasion in 2001 but still control a significant portion of the country. The ongoing war between the government and the Taliban has contributed to the perpetuation of Afghanistan's problematic human rights record including complications of women's rights, with numerous abuses committed by both sides, such as the killing of civilians.
Afghanistan is a unitary presidential Islamic republic. The country has high levels of terrorism, poverty, child malnutrition, and corruption. It is a member of the United Nations, the Organisation of Islamic Cooperation, the South Asian Association for Regional Cooperation, the Group of 77, the Economic Cooperation Organization, and the Non-Aligned Movement. Afghanistan's economy is the world's 96th largest, with a gross domestic product of $72.9 billion by purchasing power parity; the country fares much worse in terms of per-capita GDP, ranking 169th out of 186 countries as of 2018.
The root name "Afghān" is, according to some scholars, derived from the name of the Aśvakan or Assakan, ancient inhabitants of the Hindu Kush region. Aśvakan literally means "horsemen", "horse breeders", or "cavalrymen". Historically, the ethnonym Afghān was used to refer to ethnic Pashtuns. The Arabic and Persian form of the name, Afġān was first attested in the 10th-century geography book Hudud al-'Alam. The last part of the name, "-stan" is a Persian suffix for "place of." Therefore, "Afghanistan" translates to "land of the Afghans," or "land of the Pashtuns" in a historical sense. The modern Constitution of Afghanistan, however, states that the word "Afghan" shall apply to every citizen of Afghanistan.