Report: The Closed Sea That Became Iran's Military Oxygen Pipe
The military alliance between Moscow and Tehran is taking a new form: Russia is transferring drone components to Iran via the Caspian Sea, helping it restore capabilities damaged during the war against the U.S. and Israel. This route, previously used by Iran to supply Russia, is now operating in the opposite direction.
The military alliance between Moscow and Tehran is taking a new form: Russia is transferring drone components to Iran via the Caspian Sea, helping it restore capabilities damaged during the war against the U.S. and Israel. This route, previously used by Iran to transfer drones, components, and ammunition to Russia for the war in Ukraine, is now being used by Moscow to assist in the rearmament of Tehran, as reported today (Tuesday) by NBC.
The Caspian Sea is becoming a strategic supply artery for Iran. According to reports based on American sources, Russia is sending components intended for Iranian drones across the sea, helping Tehran rebuild its offensive capabilities after the damage sustained in the war.
This marks a reversal of the relationship seen in the early years of the war in Ukraine. While Iran previously supplied Russia with Shahed drones and military equipment, Moscow is now using the same logistical artery to flow equipment in the opposite direction.
According to American officials, Iran lost a significant portion of its drone inventory during the fighting. A report published in May estimated that Tehran had lost about 60% of its drone stockpile.
The choice of the Caspian Sea is not accidental. It is a closed body of water surrounded by five countries: Russia, Iran, Azerbaijan, Kazakhstan, and Turkmenistan. Unlike the Persian Gulf, this region offers limited opportunities for the U.S. and its allies to enforce sanctions or intercept shipments.
On the Russian side, the ports of Astrakhan, Olya, and Makhachkala are used, while on the Iranian side, Bandar Anzali and Amirabad are key hubs. The route allows ships to move directly between Russia and Iran, bypassing the Strait of Hormuz and sea lanes controlled by Western forces.
The importance of these ports was highlighted in November 2024, when the European Union added Amirabad and Anzali to a list related to the transfer of Iranian military technology to Russia. The EU also imposed measures on Russian shipping companies involved in transporting weaponry.
The military significance of the route has also drawn Israeli strikes. On March 18, Israel attacked vessels, a command center, and a shipyard in the port of Bandar Anzali. Despite these actions, continued reports of component shipments indicate that the axis has not been fully severed.
A CSIS analysis determined that routes through the Caspian region are attractive to Iran because they bypass the bottlenecks where U.S. interception capabilities are concentrated. In August 2025, Ukraine announced it had attacked the Russian cargo ship Port Olya-4, which was carrying components for Shahed drones.
This development illustrates the two-way nature of the military connection between Russia and Iran. Moscow, having gained experience in producing and operating Iranian systems, is now in a position to help Tehran restore its military power. The Caspian Sea remains the link connecting the two countries in this deepening partnership.
