Of note, on the bilateral level, Iran’s relations with both Russia and China have in various aspects been developing like before. Hence, the idea that SCO accession could offer anything further to Iran is a hard sell.
Another important point is that within the SCO itself, the leadership rivalry between Moscow and Beijing — and their differing views on whether to prioritize security or economic concerns on the organization’s grand agenda — has thus far prevented the organization from being fully functional in practice.
Furthermore, the decision on the accession of India and Pakistan has already been finalized. Given the constantly strained relations between the two South Asian neighbors, this move could create even more rivalries within the organization and eliminate its geostrategic importance altogether. This is another key factor that should induce Iran to think twice about joining.
The present Iranian government appears well aware of these considerations. Indeed, since the beginning of the presidency of Hassan Rouhani in August 2013, previous insistence on the need to join the SCO has ceased. If anything, the level of Iran’s participation at the recent SCO summit in Uzbekistan is a good indication of this step back. Unlike the Ahmadinejad era, during which the president would attend almost every annual SCO summit, Iran now sends its foreign minister.
Thus, it could be argued that accession to the SCO presents no particular security, economic or strategic advantages to Iran. As such, if Tehran is eager to participate in multilateral cooperation in Asia, it is better to pursue such an objective through focus on engagement with other economic initiatives, such as Russia’s Eurasian Economic Union and China’s One Belt, One Road. At least in the case of the former, the Russian president has already declared that he welcomes Iran’s participation.