In this paper, we aim to understand how transition towards sustainability processes might arise and develop in a post-conflict country. We analyse the case of the development of renewable energy in Lebanon to understand how green initiatives might emerge, without a prior master plan in a country that was torn by war. We focus on the structured action being developed in cooperation with the UNDP to enable Lebanon to fulfil its international commitment of achieving a 12% target of renewable energy in its energy mix by 2020. The process began in 2010 with the installation of photovoltaic systems in the capital Beirut. This initiative has led to the creation of what appears to be today a viable business ecosystem which makes the 12% a target that seems within reach. We analyse this “success” using a sociotechnical approach with a neo-institutional perspective. We show that the support of international agencies in post-conflict reconstruction modifies radically the dynamic evolution of sociotechnical regimes and links the transition context to the different phases leading to the institutionalization of a new technology. Finally, we propose a framework based on a critical interpretation of the multi-level perspective for the sustainability transition process in post-conflict countries.