This chapter is the first of three focusing on how business value chains are woven into the bedrock of sustainability. Security of supply is becoming a defining constraint for economic strategy as sustainability pressures intensify. Water, energy, food, and critical minerals are no longer guaranteed inputs but increasingly scarce, interdependent, and vulnerable to climate and geopolitical shocks. Water scarcity, destabilised hydrological cycles, and rising demand threaten agriculture, industry, and social stability. Energy systems must balance decarbonisation with reliability amid extreme weather, grid fragility, and concentrated supply chains. The surge in demand for critical minerals essential to clean technologies introduces new geopolitical dependencies and market volatility. Food systems, tightly coupled to water, energy, and trade, face growing exposure to climate events and export restrictions. Ecosystem degradation further undermines the natural capital that underpins all supply chains. As a result, resilience — rather than efficiency — must now guide policy and business decisions as physical limits increasingly shape economic outcomes.