One of the remarkable aspects of the “big bang” expansion of BRICS (Brazil, Russia, India, China and South Africa) announced at the summit in Johannesburg, South Africa, this week, is the invitation to join the group issued to, among others, Iran and Saudi Arabia — geopolitical rivals in the Persian Gulf.

After Iran became a full member of the Shanghai Cooperation Organization (SCO) in 2022, and Saudi Arabia a “dialogue partner” to this China-led Eurasian security forum (with the prospect of full membership), BRICS is now the second multilateral platform for cooperation and dialogue between Riyadh and Tehran.

Simultaneous accession to BRICS and, in the future, Saudi accession to SCO, could further enhance the incipient process of bilateral normalization between Tehran and Riyadh. Skeptics point to the alleged dysfunctionality of BRICS that, unlike the European Union or NATO, lacks clear accession criteria and gathers countries that seemingly have little in common except some vaguely defined dissatisfaction with the U.S.-led “rules-based order.”

Yet, this flexibility and the absence of rigid “rules” can be more of an asset than a defect.  For Iran and Saudi Arabia, what counts is a trajectory, a prospect for a long-term normalization rather than immediate results and unrealistic commitments and expectations.

In other words, a forum like BRICS, where both countries can interact on an equal footing and all decisions are taken by consensus, could prove to be a suitable arena to incrementally build mutual confidence.

Such a prospect, of course, is far from inevitable. The reactions from Tehran and Riyadh to the invitation to join BRICS were markedly different in tone and substance. While Iranian officials were exultant about the prospect, the Saudis were much more cautious and pointed to the need to further study the details of what membership would entail before confirming their intention to join.

This disparity stems from both countries’ different needs: for Iran, it is imperative to overcome what Quincy Institute Executive Vice President Trita Parsi called the U.S. “gatekeeping role” in the international community. Seen from this angle, joining BRICS is diplomatically far more impactful for Iran than the SCO. Unlike the latter, BRICS is truly global and cannot be dismissed as a club of Eurasian autocracies. There are democracies among its members — Brazil, India, South Africa, and, if membership is confirmed after the elections later this year, Argentina.

None of these countries can be classified as an anti-American autocracy. Yet their Western ties and democratic governance were not obstacles in their greenlighting of Iran’s accession. Tehran is right to see it as a diplomatic success.

Saudi Arabia, on the other hand, does not need to break any diplomatic ceilings — to the contrary, it is being courted by the U.S. for a deal that would reportedly entail, among other things, U.S. security guarantees for the kingdom in exchange for Saudi-Israeli normalization. Yet, joining BRICS fits into a broader Saudi strategy of diversifying foreign ties, and, in particular, building a closer relationship with China. The chances, therefore, are that Saudi Arabia, after taking a requisite diplomatic pause, will accept the BRICS invitation.

Matters may be more complicated with joining the SCO, as reportedly one of the U.S.’s quiet demands on Saudi Arabia in exchange for security benefits on offer is to stay away from China’s orbit. In that context, full SCO membership may be a bridge too far for Riyadh. Yet such membership is not imminent anyway. Meanwhile, SCO dialogue partner status that the kingdom obtained earlier in 2023 provides it another link to Iran, a permanent member.     

Ultimately, however, platforms like BRICS and SCO can only help, but not substitute for the bilateral Saudi-Iranian normalization track. While the Tehran-Riyadh dialogue proceeds with high-level meetings of foreign ministers and top defense officials, it is still in its early stages. Despite optimistic timetables, the work of the diplomatic legations in both countries has not yet fully resumed.

The controversies over the disputed Arash/Dorra gas field, which pits Saudi Arabia and Kuwait against Iran have not yet been resolved. Saudi Arabia insists that, in the long run, Iran will have to address its regional forward-defense strategy — that is, its reliance on non-state proxies and allies that Saudi Arabia and other GCC countries see as a threat, without specifying what corresponding concessions Riyadh would be willing to countenance. After decades of tensions dating back to 1979, mutual distrust runs deep, and its structural reasons are still far from being removed.

Perhaps, most urgently for Tehran at this stage, Saudi Arabia has made it clear that it won’t seek exemptions from U.S. sanctions on Iran unless there is some sort of a nuclear deal between Washington and Tehran — an unlikely event given the U.S. is entering a new election season when neither political party will want to appear solicitous of Iran. The implication is that the anticipated economic benefits from the Saudi-Iranian rapprochement may be slow in materializing.

In view of these deeper entanglements, it is likely that Saudi-Iranian relations will experience further ebbs and flows. If they take a more confrontational turn again, it might negatively affect the cohesion of BRICS, with both sides using whatever leverage they have to the detriment of the other. In that case, the current members of BRICS may come to rue the decision of importing geopolitical rivalries from the Persian Gulf into their group.

That would be particularly harmful for the self-perception of BRICS as a forum for inter-state cooperation, in contrast to the Western-dominated institutions, such as the OECD, Bretton Woods, and NATO, based on U.S. hegemony.

Yet this should not necessarily be the case. Relations between China and India are similarly not devoid of tensions due in part to a a long-standing border dispute: as recently as 2020, scores of Indian and Chinese soldiers were killed in an armed skirmish. Both countries also compete for leadership in the Global South. Yet both Beijing and Delhi also seek to preserve dialogue and close economic relations. So far, they have not let their differences stand in the way of BRICS, and this week’s ambitious expansion of the group is proof that pragmatism prevails.

There is no reason why Tehran and Riyadh cannot manage their differences in similar fashion. China, a leading power in both BRICS and SCO, also played a crucial role in kickstarting the Saudi-Iranian rapprochement and can be expected to invest in this process further.

Most importantly, both Tehran and Riyadh see an abiding national interest in proceeding with the de-escalation and normalization of ties. In the near future, at least, it looks likely that this trajectory will be preserved, despite the pitfalls on the way. Shared membership in BRICS — and, in the future, possibly in the SCO, too — provides additional venues for the confidence-building process.