If we check the politics at the door and just talk about history, the facts don&#x27;t change.<p>The Mediterranean possessed few unique trade goods that were practical for long-distance trade.  There are copper and tin mines in China and India.  You can as easily get ivory from Indian elephants as North African ones.  Tyrian purple appears to not have been very popular in areas that produced indigo.  Shipping Egyptian wheat doesn&#x27;t make a great deal of sense when you are already producing surpluses in the Indus, Yangtze and Yellow river valleys.  Chinese porcelain was comparable, if not superior to Attic pottery.  It would be insanely extravagant to import Italian or Greek marble when you have to transship it across the Sinai peninsula.  Garum was a massively important Roman luxury good, but you can make fermented fish sauce elsewhere, or use soy-sauce to get your MSG.  In an era of astronomically high transport costs, only the rarest, highest-value goods made any sense at all to transport long distances.<p>So there were raw goods that the Roman elites desired that could not be locally sourced, because they were, by geographical accident, only produced in other places.  Elites in other places happened to have these goods locally, and there was very little that was uniquely produced in the Mediterranean that could be exchanged for those goods.  So they used hard-currency, because everybody likes shiny metal.<p>The Chinese opium trade was a huge deal, because at the time, the American precious metal mines were just about played out, and revolution throughout the old Spanish colonies were further disrupting supply.  Although the heydey of importing opium into China didn&#x27;t last very long - within a couple of decades, China was producing more locally grown opium poppies than were ever imported.