Securing a stable and reliable energy supply in affordable and environmentally friendly conditions is the ultimate objective of energy law and policy. Energy systems must function ‘free from serious risk of major disruption of service’. Consumers must have access to a sufficient quantity of energy at socially and economically acceptable prices, but at the same time, efforts to mitigate climate change, protect local air quality and address water scarcity must not be undermined. States must therefore ensure that adequate investments are made in energy production and network capacity, without imposing an unreasonable financial burden on industry and the general public. The stakes are high. The failure to deliver energy security undermines economic development and social and environmental protection, and can also threaten social peace and stability.