This exhibition showcases over 200 objects from Afghanistan, many of them of great beauty, produced between 4,000 and 1,800 years ago
Afghanistan was, as the exhibition's subtitle puts it, "the crossroads of the ancient world". A network of trade routes that joined China and India with Europe - sometimes called the "Silk Road" - ran through the country. For 3,000 years both ideas and commodities, including luxuries like jade and silk, moved along its 6,500 kilometres of roads.
This trade - and the links between the many different cultures involved - lies behind almost all the objects on display. The earliest are gold and silver vessels from around 2,000 BC. The design of one of these vessels resembles that of objects found in Mesopotamia - present day Iraq - some 2000 kilometres to the west. Even at this early stage of civilisation people from different cultures were travelling, trading and exchanging ideas.
But Afghanistan's location between empires leads to a second theme running through the exhibition - how often it has been invaded. In around 300 BC, for example, Alexander the Great conquered the territory, and one of his generals founded the Greek city of Ai Khanum, complete with an amphitheatre, a gymnasium and temples to Greek gods. But, as well as Greek culture, objects from this period include a shell disc showing an Indian legend, and a wall plaque decorated in an Egyptian style.
One hundred and fifty years later Ai Khanum was destroyed by Central Asian nomads. The nomads were skilled craftspeople. They produced the delicate golden crown on the exhibition posters - delicate because it comes apart into six pieces and packs flat so it can be transported.
In time they settled, and in the 1st to 3rd centuries AD they established their own kingdom with its summer capital at Bagram - now the location of the notorious US Bagram Air Base, where hundreds of prisoners have been tortured. The objects found at Bagram represent an astonishing number of cultures. There are wine pitchers imported from Egypt - part of the Roman Empire at the time - and beakers showing the Egyptian goddess Isis, as well as statues of Indian goddesses and ivory plaques showing the previous lives of the Buddha.
But these cultures did not remain separate - one figure of the Greek goddess Aphrodite depicts her with a mark in the centre of her forehead, an Indian cultural practice both then and today. It's easy to imagine that multiculturalism is something new, attempted only in the last few decades and which - according to David Cameron - has failed. But I left the British Museum imagining merchants in Afghanistan almost 2,000 years ago, and the knowledge of every culture, from Rome to India, which they must have possessed. The desire for contact with other societies is no novelty, but as old as civilisation itself.
At the British Museum until 3 July