Shanghai Cooperation Organisation (SCO) members are meeting for the first time this weekend since the inclusion last year of rivals India and Pakistan raised fears that the bloc could struggle to function.
The bloc, which comprises China, Russia, the Central Asian states of Kazakhstan, Tajikistan, Uzbekistan and Kyrgyzstan and the two new additions, makes up some 40 per cent of the world's population and 20 per cent of its GDP. The summit in Qingdao in eastern Shandong province is expected to discuss a new consensus to promote unity and mutual trust among other things.
What has added buzz is talk that North Korean leader Kim Jong Un might visit to meet Chinese President Xi Jinping and Russian President Vladimir Putin ahead of his summit with United States President Donald Trump on June 12.
The SCO has come a long way since its inception in 1996. The Shanghai Five, as it was known then as Uzbekistan was not a member, aimed to delineate disputed borders of the former Soviet states and with China after the break-up of the Soviet Union. In 2001, it included Uzbekistan and changed its name to the current one. It began to focus on regional security issues and coun-ter-terrorism in the aftermath of the Sept 11 terror attacks in the US.
In recent years, the SCO began to include economic cooperation that has spurred trade within the bloc.
But progress has been slow because of the divergent interests of its members, particularly Russia and China, say analysts.
While Russia saw it as a vehicle with which to push back against Western influence, the Chinese regard it as a platform for gaining economic influence in Central Asia.
Other states had issues as well, including water disputes between Tajikistan and Uzbekistan and ethnic conflict between Kyrgyzstan and Uzbekistan.
Russia, wary of China's promotion of a free-trade area and a joint development bank as ways to gain influence in Central Asia at its expense, dragged its feet over these.
To get round this, China started to engage other SCO states bilaterally and create multilateral institutions like the Asian Infrastructure Investment Bank and projects like the Belt and Road Initiative (BRI).
Still, progress has been made and cooperation has strengthened, pointed out Professor Yang Shu of Lanzhou University.
Now, with the inclusion of India and Pakistan, things might get more complicated. India was brought in by Russia to dilute China's growing influence in the bloc and China agreed on the condition that its partner in South Asia, Pakistan, be included.
Not only are these two South Asian countries bitter rivals, but China and India also have a border dispute and are increasingly competing for influence in the region.
It could be more difficult for SCO members to reach consensus on more contentious issues and to find cohesion, analysts have said.
China, which sees the SCO as a vehicle for advancing the BRI, will be eager for resolutions at the summit that reference the initiative, noted Mr Jonathan Hillman of the US think-tank Centre for Strategic and International Studies. But with India sceptical about the BRI, these would not be unanimously supported and there would be "awkward omissions" , he said.
Overall, said Mr Derek Grossman of the Rand Corporation: "It will be very difficult to deal with the challenge of growing bilateral geostrategic competition created by the BRI and simmering border disputes and mutual suspicions."
However, with the SCO's prime movers, China and Russia, having found new reasons to cooperate under its auspices, the bloc is unlikely to lose momentum any time soon.
Renmin and Lanzhou universities noted recently that Russia, which faced sanctions from the West after its intervention in Ukraine, now placed greater emphasis on its relationship with China and the role of the SCO. It added that the US gave impetus to China and Russia developing even closer ties by characterising the two countries as strategic rivals and revisionist powers. "The SCO has become an important platform for China and Russia to coordinate and cooperate in order to resist pressure from the West," said their report.
Prof Yang said: "Don't have too high expectations of the organisation, but don't write it off either."