- Russia has hesitated to buy ballistic missiles from Iran out of concern that the US would provide Ukraine with long-range rockets.
- Iran has sent hundreds of armed drones to Russia that have been used to attack Ukrainian critical infrastructure.
- Western capitals believe Tehran is open to further military co-operation with Moscow.
- US has recently stepped up warnings over deeper Russia-Iran military co-operation.
- Russian military was already concerned about its ability to sustain the war.
Russia and Iran hesitate over co-operation as west warns of costs
Russia and Iran have hesitated to cooperate militarily due to US warnings, with Russia concerned about its ability to sustain the war.