Afghanistan is a mountainous landlocked country at the crossroads of Central and South (Southern) Asia. Some of the invaders in the history of Afghanistan include the Maurya Empire, the ancient Macedonian Empire of Alexander the Great, the Rashidun Caliphate, the Mongol Empire led by Genghis Khan, the Timurid Empire of Timur, the Mughal Empire, various Persian Empires, the British Empire, the Soviet Union, and most recently the United States with a number of allies in response to the September 11 attacks. A reduced number of NATO troops remained in the country in support of the government under the U.S.–Afghanistan Strategic Partnership Agreement. Just prior to American withdrawal in 2021, the Taliban regained control of the capital Kabul and most of the country. They changed Afghanistan's official name to the Islamic Emirate of Afghanistan.
Purpose
From a geopolitical perspective, controlling Afghanistan is vital in controlling the rest of Southern Asia, or getting a passage through Central Asia, reflecting its geographic position in the region. Afghanistan played an important part in the Great Game power struggles. Historically, the conquest of Afghanistan has also played an important role in the invasion of India from the west through the Khyber Pass.
History of Afghanistan
Persian conquests
While relatively little detail is known, parts of the region of modern day Afghanistan came under rule of the Median kingdom for a short time.
Afghanistan fell to the Achaemenid Empire after it was conquered by Darius I of Persia. The area was divided into several provinces called satrapies, which were each ruled by a governor, or satrap. These ancient satrapies included: Aria (Herat); Arachosia (Kandahar, Lashkar Gah, Bamiyan and Quetta); Bactriana (Balkh); and Gandhara (Kabul and Peshawar).
Greek conquest and Kushan invasions
Alexander the Great invaded what is today Afghanistan in 330 BC as part of war against Persia. Comprising the easternmost satrapies of Persia, Afghanistan provided some challenging battles in his conquest of the remaining lands of Persia. Renamed Bactria, and settled with his Ionian veterans, Alexander began his invasion of India from what is now Jalalabad, attacking the Indus River basin through the Khyber Pass. Several cities in Afghanistan are named for Alexander, including Alexandria Arachosia, now called Kandahar (a contraction of Iskandahar).
Following the death of Alexander and the partition of his kingdom, the Province of Bactria was under the rule of Alexander's former general, Seleucus, who now formed the Seleucid Dynasty, with its capital in Babylon. But the Greek Soldiers in Bactria, based on the remoteness of their territory, declared independence, defeated Seleucid armies sent to reconquer them, and founded the Greco-Bactrian kingdom, which lasted for more than three centuries in Afghanistan, and western India. This Greek kingdom called Bactria carried on Greek culture while completely cut off from Europe for three centuries. One of the cities, Ai-Khanoum was excavated in 1970s, showing a complete Greek city with an acropolis, amphitheater, temples, and numerous statues. Greek art has been found in Bactria showing influence from Indian Buddhist art creating something of an hybrid artistic style. Bactrian King Menander I converted to Buddhism after staging multiple theological and philosophical debates between his Greek priests and Indian Buddhist monks. Menander I is remembered in Buddhist Sutras as "King Milinda of the Yunani." The Ionian origin of the Greek veterans who settled Bactria is remembered to this day by the Afghan word for Greeks, which is "Ionani." Bactrian Greeks left a legacy of coinage, architecture, and Buddhist art, which comprised the Gandhara culture, especially the Greco-Buddhist art affecting all of East Asia to this day. The last Greek Kingdom in Afghanistan was conquered by the Kushan invaders in the first century AD, a full three centuries after Alexander. But Greek language continued to be used by the Kushans in their coinage for the next several centuries.