India, Sept. 11 -- From a four-member economic acronym coined in 2001, BRICS has evolved into a powerful Global South platform spanning 11 members and 10 partners. As India hosts its 18th summit amid geopolitical conflict, trade disruptions and US pressure, the bloc faces a defining test: can it turn growing heft into meaningful outcomes?

When Goldman Sachs economist Jim O'Neill coined the acronym BRIC in 2001 to group the emerging economies of Brazil, Russia, India and China, he could hardly have envisioned its evolution into a large, influential diplomatic bloc over a quarter of a century later.

Now known as BRICS after South Africa joined it in 2010, the grouping has expanded to include 11 member states and 10 partner countries. Over...