Afghanistan (Pashto/Dari: افغانستان, Pashto: Afġānistān, Dari: Afġānestān ), officially the Islamic Republic of Afghanistan, is a landlocked country located in South-Central Asia. Afghanistan is bordered by Pakistan in the south and east; Iran in the west; Turkmenistan, Uzbekistan, and Tajikistan in the north; and in the far northeast, China. Its territory covers 652,000 km2 and much of it is covered by the Hindu Kush mountain range, which experiences very cold winters. The north consists of fertile plains, while the south-west consists of deserts where temperatures can get very hot in summers. Kabul serves as the capital and its largest city.
Human habitation in Afghanistan dates back to the Middle Paleolithic Era, and the country's strategic location along the Silk Road connected it to the cultures of the Middle East and other parts of Asia. The land has historically been home to various peoples and has witnessed numerous military campaigns, including those by Alexander the Great, Mauryas, Muslim Arabs, Mongols, British, Soviets, and since 2001 by the United States with NATO-allied countries. It has been called "unconquerable" and nicknamed the "graveyard of empires". The land also served as the source from which the Kushans, Hephthalites, Samanids, Saffarids, Ghaznavids, Ghorids, Khaljis, Mughals, Hotaks, Durranis, and others have risen to form major empires.
Turkmenistan ( or ; Türkmenistan, ), formerly known as Turkmenia, officially the Republic of Turkmenistan, is a country in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north and east, Afghanistan to the southeast, Iran to the south and southwest, and the Caspian Sea to the west. Ashgabat is the capital and largest city. The population of the country is 5.6 million, the lowest of the Central Asian republics and one of the most sparsely populated in Asia.
Turkmenistan has been at the crossroads of civilizations for centuries. In medieval times, Merv was one of the great cities of the Islamic world and an important stop on the Silk Road, a caravan route used for trade with China until the mid-15th century. Annexed by the Russian Empire in 1881, Turkmenistan later figured prominently in the anti-Bolshevik movement in Central Asia. In 1925, Turkmenistan became a constituent republic of the Soviet Union, Turkmen Soviet Socialist Republic (Turkmen SSR); it became independent upon the dissolution of the Soviet Union in 1991.