WASHINGTON (Reuters) – US military planners will have to delve deep into the history books to find the last Western commander to conquer Afghanistan. It has been 2,300 years since Alexander the Great swept through the Afghan deserts and mountains to overcome hostile tribes on his long march to India. He was one of the first military greats of history to prove their worth in Afghanistan, often seen as the key to control of Eurasia. In contrast to the US military’s reluctance to commit troops to a long ground campaign in Afghanistan, the headstrong Alexander had no qualms about exposing his forces to extreme danger when he invaded in 330 BC. At the age of 26, he took 32,000 troops under his direct command into Afghanistan, then a group of provinces in the crumbling Persian Empire. Three years later he had built a string of cities around the country, probed deep into Central Asia and was poised to swoop into the plains of what is now Pakistan and India. Alexander faced the same problems as all invaders of Afghanistan: the harsh climate and geography and local people who enjoy a fight, said military historian Raymond Callahan. Historians say Alexander’s military genius and sheer force of character drove his mostly Greek troops through the hardships. While the main point of the Greek invasion was to clear his path to India, Alexander left a permanent mark in Afghanistan with a series of settlements bearing his name. The southern city of Kandahar, the stronghold of today’s Taleban militia, has close connections to Alexander, although historians disagree whether he was the city’s founder. The Greeks’ most useful ally in the Afghanistan campaign was Oxyartes, a former enemy who later persuaded tribal leaders not to oppose Alexander. Friendship was sealed between the two men when Alexander married his ex-foe’s daughter Roxana. One of the most successful strategies Alexander employed was to marry the daughter of a tribal chief, an option that is unavailable to President George W. Bush and British Prime Minister Tony Blair, said analyst Callahan.