Russia and Iran are building a new transcontinental trade route that stretches from the eastern edge of Europe to the Indian Ocean - a 3,000-kilometer passage that defies any foreign intervention.

It shows how two of the world's most sanctioned countries are resisting Western pressure and creating trade networks that are protected from disruption. The route crosses rivers and railroads connected by the Caspian Sea, the inland body of water dominated by Russia and Iran.

Ship tracking data collected by the Bloomberg news agency shows that dozens of Russian and Iranian vessels - including those subject to sanctions - are already plying the route. Tens of billions of dollars are being invested to increase trade volumes.

"This is about creating sanctions-proof supply chains throughout," says Maria Shagina, an expert on sanctions and Russian foreign policy at the International Institute for Strategic Research in London. Ships plying the Don and Volga rivers traditionally trade energy and agricultural goods. Iran is the third largest importer of Russian grain. The two countries have announced a number of new business agreements, including in turbines, polymers, medical supplies and automotive parts.

U.S. officials are also watching the corridor closely, as it could also be used to transport Iranian weapons used in Russia's war against Ukraine. "This is an extraordinarily damaging, reckless decision they've made," said Robert Malley, the U.S. government's Iran envoy. "It's important that we draw attention to it."

Image by Gerd Altmann