This chapter offers an original account of Environmental Impact Assessment (EIA) as a technology that scripts collective action through black-boxing the politics of governance. After tracing the global trajectory of the instrument, the chapter looks at EIA struggles in the case of pulp mills on the River Uruguay. As actors seeking to halt projects because of their potential harmful impact follow the choreography of EIA, the authoritative governance script is reinforced rather than undermined. There is a tragic aspect to this, in that those wishing to block a project are actually making it stronger. This points to a subtle de-politicization resulting from the evolution of instruments in use, and a need for their re-politicization.