The book examines the duties of sovereign states, exemplified by resource-rich developing countries, inherent in Permanent Sovereignty over Natural Resources (PSNR), in relation to petroleum development in Nigeria. The duties of states are mainly of national development and the well-being of the citizens. The book discovers that these duties relate to the primary duties of governments expressed in the social contract of governance and enshrined in the Nigerian Constitution, and that Nigeria is in breach of these duties in the course of petroleum development, which duties translate to unfulfilled obligations owed to the country, its citizens and the oil-rich Delta region. It reveals that ineffective laws, non-compliance with laws and inefficient institutions, entrenched in bad governance, impair Nigeria from adequately performing its duties ingrained in PSNR. It recommends a need for improvement of government social responsibility, towards good governance, good environmental governance, energy efficiency, greener economy, greater human well-being, sustainable communities and sustainable development in Nigeria and a fairer, more humane, harmonious, prosperous and peaceful world.