When leaders of the BRICS nations gathered for group photos at the end of their summit in Johannesburg last week, it offered a glimpse of the contours of the new world order Beijing is trying to shape.

Standing at the front and center was Xi Jinping, China's powerful leader, surrounded by a stage of leaders from emerging markets and developing countries across Africa, Asia and Latin America.

The summit was the largest the BRICS have ever held, with more than 60 countries attending alongside member nations Brazil, Russia, India, China and South Africa.

Flanking the current BRICS leaders were counterparts from Argentina, Ethiopia, Iran, Saudi Arabia, Egypt and the United Arab Emirates -- who had just been invited to join the club.

The development is a big win for Xi, who has long pushed to expand the bloc and its clout despite reservations from other members such as India and Brazil.

The expansion, the first since South Africa was added in 2010, is set to more than double the group's membership and significantly extend its global reach -- especially in the Middle East.

"This makes China the clear winner," said Steve Tsang, director of the SOAS China Institute at the University of London. "Getting six new members is a significant move in its preferred direction of travel."

For Beijing, as well as Moscow, the expansion is part of its drive to forge the loose economic grouping into a geopolitical counterweight to the West -- and Western institutions such as the G7.

That mission has become all the more urgent over the past year given China's escalating rivalry with the United States, as well as the ramifications of the Ukraine war -- which saw Beijing further estranged from the West over its support for Moscow.

As shown by the BRICS expansion and the long waiting list to join, Xi's offer of an alternative world order is finding receptive ears in the Global South, where many countries feel themselves marginalized in an international system they see as dominated by the US and its wealthy allies.

Echoing their demand for a larger say in global affairs, the BRICS leaders' declaration repeatedly called for "greater representation of emerging markets and developing countries" in international institutions -- from the United Nations and its Security Council to the International Monetary Fund (IMF) and the World Bank.

Xi, who peppered his speeches at the summit with criticism of US "hegemony," hailed the expansion as "historic" and "a new starting point for BRICS cooperation."

Happymon Jacob, a professor of international studies at New Delhi's Jawaharlal Nehru University, said the expansion highlights a shift in global geopolitical fault lines.

"Being a leader of non-Western forums and the Global South, which in general is dissatisfied with the US-led institutions, will invariably help China become a counterweight to the US and the world order led by the US," he said.

The new members

But a wider membership also raises questions about the cohesion and coherence of BRICS, whose existing members already differ widely in political systems, economic prowess and diplomatic goals.

"I am skeptical in terms of the effectiveness of the organization after the expansion, and whether in the end the expansion is more symbolic than substantive," said Yun Sun, director of the China program at the Stimson Center in Washington.

"The more members there are, the more interests the organization needs to reconcile and accommodate."

That is particularly true for a consensus-based organization like BRICS, where decisions are only made if all members agree.

The new joiners are a somewhat disparate group. Two are very much struggling economies. Argentina, a serial defaulter that has long struggled with inflation and currency crises, is the biggest borrower from the IMF. Egypt, which is facing its own economic crisis, is the IMF's second largest debtor.

Ethiopia, the second most populous country in Africa and once one of the continent's fastest-growing economies, is reeling from the devastation of a two-year civil war in the country's Tigray region, which ended in December, amid evidence of widespread human rights abuses.

The enlarged bloc will also include three of the world's largest oil exporters: Saudi Arabia, the UAE, and Iran.

The former two are traditionally close allies of America, but have recently fostered closer ties with China which has stepped up its presence in the region amid a perceived power vacuum left by the US.

Iran and Saudi Arabia are arch rivals, though earlier this year they restored diplomatic ties in a deal brokered by China.

That contrasts heavily with a more unified bloc like the G7 which is comprised of like-minded democracies with large industrialized economies.

Helena Legarda, lead analyst at the Mercator Institute for China Studies, a think tank in Berlin, said it is unclear to what extent the BRICS expansion will increase the value and influence of the group.

"Without a shared ideology and clear overarching goal, it is likely that the addition of six new members may instead make BRICS a more divided group."

Internal divisions

A key dividing issue is the anti-US agenda pushed by China and Russia, which has been strengthened with the inclusion of Iran.

India and Brazil have expressed concerns about the bloc potentially becoming too anti-Western and dominated by Beijing, and some of the new members may be similarly skeptical, according to Legarda.

"Despite the clear geopolitical objectives that China has for the group, many other developing and emerging economies don't see BRICS as an exclusively geopolitical body. They are also motivated by economic opportunities and the chance of securing privileged access to the Chinese and other markets," she said.

But China is battling its own economic woes at home -- from a spiraling property crisis and mounting local government debt to record youth unemployment and an ageing population. Many economists believe the world's second largest economy is entering an era of much slower growth, which can have a profound impact on the global economy.

The BRICS expansion is also likely to fuel competition -- and potential friction -- between China and India, whose ties have already been strained by a simmering border conflict.

"Sino-Indian competition for the leadership of the Global South is now bound to sharpen with China having a clear advantage," said Jacob in New Delhi.

"While India does have good relations with all of the new BRICS members, China's deep pockets and its ability to fill the post-American vacuum especially in the Middle East would mean that China will be able to influence the institution far more than India could," he added.

The rivalry and tensions between China and India, as well as between Iran and Saudi Arabia, mean that issues they can agree upon and jointly act upon are unlikely to be significant in number and in nature, said Sun with the Stimson Center.

"The expansion certainly builds an image of a growing coalition vis-a-vis the West, but having more countries in one organization does not equate to more effectiveness."