First, Russia’s war in Ukraine has created a major demand for air defense systems at home. Moscow is prioritizing its own military needs, diverting production away from foreign orders.

Second, there is a political balancing act. Russia is wary that heavily arming Iran could escalate tensions in the region and harm its relations with Gulf states and Israel, with whom it maintains sensitive communication channels.

There are also reports that Moscow has avoided activating mutual defense agreements with Iran, using legal interpretations to argue that strikes on Iran do not constitute a full-scale invasion requiring intervention.