This paper highlights the profound external water dependency of high-income countries, with 40–94% of their water footprints sourced from outside their borders. These external footprints are heavily concentrated in regions facing high water and climate vulnerability. Critically, half of the Global North’s external ‘blue’ water footprint is unsustainable, contributing to environmental degradation, resource depletion, and conflict. This poses significant risks to global water security and the resilience of key supply chains.
