In this interview for the Global Governance Innovation Platform (GGI), Nicholas Vaughan traces the origins of the International Finance Facility for Education (IFFEd), launched under the leadership of Gordon Brown to address the financing gap for SDG 4 on education. Developed in partnership with major multilateral development banks, IFFEd uses a novel guarantee model alongside grant financing to unlock additional, more affordable lending – particularly for “missing middle” countries that face a sharp decline in education investment as they transition from concessional to market-rate loans. Vaughan highlights how this blended finance approach not only sustains investment in human development, but is also being adapted across sectors, with similar guarantee models now informing climate, health and broader development finance initiatives within institutions like the World Bank and Asian Development Bank.