This book investigates the strategic use of public procurement as a way to establish “buying green” as a common practice – not only in the EU, but all over the world. However, imposing environmental requirements may affect the conditions of competition between suppliers, especially between local and foreign ones. This is particularly relevant for signatory states to the Government Procurement Agreement (GPA), a plurilateral WTO agreement that aims at liberalizing public procurement markets. So how can these countries strike a balance between trade concerns and using the environmental potential of public procurement? What scope does the GPA 2012 leave for environmental criteria and how are signatory states making use of it? The need for answers to these questions is becoming even more pressing with the increasing use of green public procurement (GPP).