Founded in Shanghai in 2001 with just six members — Russia, China, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan — the SCO has grown rapidly over the past decade. India and Pakistan joined in 2017, Iran in 2023, and Belarus in 2024.
Beyond these 10 member states, the SCO also has two observers — Afghanistan and Mongolia — and 14 dialogue partners, including Turkey, Egypt, Armenia and Azerbaijan, several of the Gulf states, and a number of other Asian states. If measured by population of its core member states, it is the world’s largest regional organisation.
Size clearly matters, but in the case of the SCO it creates problems rather than contributing to their resolution. The organisation did little in response to escalating tensions between India and Pakistan in the wake of the terrorist attacks in Kashmir that eventually brought the two long-standing rivals to the brink of nuclear confrontation.