The BRICS group expanded adding six new members on August 24 (Argentina, Egypt, Ethiopia, Iran, the Kingdom of Saudi Arabia (KSA) and the United Arab Emirates (UAE)) but one important name was missing: Indonesia.

Indonesia is also a firm ally of both Russia and China, but has shied away from rushing into becoming a BRICS member because of fears of a looming conflict between the emerging markets group and the west.

“Until a few days ago, Indonesia's accession was seen as near-certain by most BRICS watchers, and looking at GDP figures, population and geographic location, it sounded like the most sensible option,” said professor of international relations Oliver Stuenkel, of FGVRI in San Paulo.

But at the last minute, Indonesia requested not to be included as a new member. The official justification was Indonesia's ASEAN Chairmanship this year. Jakarta said it wanted to consult with other members of ASEAN on its possible admission before deciding, adding it could be included in a year or two, Anil Sooklal, South Africa’s BRICS sherpa, said in an interview. “There was ready consensus on all other countries, which made the selection very easy.”

Others have pointed to China’s aggressive vision of the BRICS as a geopolitical rival that will challenge the western hegemony as the problem, a conflict Jakarta doesn’t want to get dragged into.

Indonesia is keen to keep its economic cooperation with the leading BRICS nations but wants to wait to see how international relations with the rest of the world play out before committing to membership, experts say.

The issue of what the BRICS+ relationship with the west should be remains the one of the hardest questions the group must resolve as their views are clearly divided. China and Russia, which both already find themselves in conflict with the West, want the BRICS+ to be able to aggressively push back. India, South America and Brazil have explicitly said they don’t want conflict with the West and are for maintaining friend commercial relations.

Goldman Sachs Jim O’Neill’s original criteria for inclusion in the group, who coined the acronym in 2001, was simple: big country, big population, big GDP. By those measures, with a population of 275mn and an economy worth $1.2 trillion, Indonesia easily qualifies.

And Indonesia’s economy is also bigger than all the new members: Argentina ($641bn), Egypt ($387bn) Ethiopia ($156bn) Iran ($367bn) UAE ($499bn) and even the Kingdom of Saudi Arabia ($1.1bn). Together with the five original members, collectively the economies of the BRICS+ group are worth $30.8 trillion in nominal terms, accounting for 30% of global GDP.