This book documents the influence of nongovernmental organizations on the rise of the sustainable development movement in international politics. It adds to the body of scholarly research on non-governmental organizations, by examining their political influence during the first two decades of international environmental politics - from the Stockholm Conference on the Human Environment in 1972 to the establishment of the World Conference on Environment and Development in 1982. NGOs wielded their rational moral authority to achieve their goals in attending environmental mega-conferences. In turn, these successes gave rise to a symbiotic relationship with the United Nations Environment Program and secured a seemingly permanent position at not only the negotiating table, but also the inner hallways and back rooms of the United Nations.