Energy systems should have the ability to respond promptly and flexibly to energy emergencies. Cooperation, between government agencies and between countries: e.g. IEA countries co-operate through the Agency in responding jointly to oil supply emergencies. The environmentally sustainability is also key. More environmentally acceptable energy sources need to be encouraged and developed. Improved energy efficiency can promote both environmental protection and energy security in a cost-effective manner. Continued research, development and market deployment of new and improved energy technologies make a critical contribution to achieving the objectives outlined above. Energy technology policies should complement broader energy policies. International co-operation in the development and dissemination of energy technologies, including industry participation and co-operation with non-Member countries, should be encouraged.