Afghanistan ( (listen); Pashto/Dari: افغانستان, Pashto: Afġānistān [avɣɒnisˈtɒn, ab-], Dari: Afġānestān [avɣɒnesˈtɒn]), 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 652,000 square kilometers (252,000 sq mi), 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, composed mostly of ethnic Pashtuns, Tajiks, Hazaras, and Uzbeks.
Humans lived in what is now Afghanistan at least 50,000 years ago. Settled life emerged in the region 9,000 years ago, evolving gradually into the Indus civilization (Shortugai site), the Oxus civilization (Dashlyji site), and the Helmand civilization (Mundigak site) of the 3rd millennium BCE. Indo-Aryans migrated through Bactria-Margiana area to Gandhara, followed by the rise of the Iron Age Yaz I culture (ca. 1500–1100 BCE), 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, who conquered the areas to their east as far as the Indus River. Alexander the Great invaded the region 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. Parts of the region were later ruled by the Khwarazmian, 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 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. 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 (GDP) of $72.9 billion by purchasing power parity; the country fares much worse in terms of per-capita GDP (PPP), ranking 169th out of 186 countries as of 2018.