South Africa's historic first leadership of the G20 (November 22-23, 2025) elevated Global South priorities including climate finance, debt relief, and fair mineral supply chains, yet the summit produced limited concrete results beyond tentative exploration of debt-for-climate swaps. Mounting geopolitical tensions, exemplified by Washington's rare exclusion of South Africa from the 2026 summit, threaten to fracture the forum along great-power rivalries.