Nigeria, June 12 -- Approximately 3.4 billion people live in countries that spend more on debt repayments than on health or education. In Africa, two in every three countries pay more in debt interest than they invest in the health of their citizens. The global debt system was not designed with the developing world in mind, and the cost of leaving it unreformed is one that the poorest populations continue to bear.

There is a number that should stop every country and every international creditor in their tracks. Three trillion dollars. That is the approximate sum that poorer countries send back to wealthier ones every single year, through debt servicing and tax loopholes. The Global South is not simply a recipient of global generosity, an...