The pulp mill dispute was a dispute between Argentina and Uruguay concerning the construction of pulp mills on the Uruguay River. The presidents at the time were Néstor Kirchner (Argentina) and Tabaré Vázquez (Uruguay). As a diplomatic, economic, and public relations conflict between both parties, the dispute has also affected tourism and transportation as well as the otherwise amicable relations between the two countries. The feud was unprecedented between the two countries, which have shared historical and cultural ties. Proceedings were brought before the International Court of Justice as a case formally named Pulp Mills on the River Uruguay (Argentina v. Uruguay). It ruled that, although Uruguay failed to inform Argentina of the operations, it did not pollute the river, so closing the pulp mill would be unjustified. The conflict ended in 2010, during the presidencies of Cristina Fernández de Kirchner (Argentina) and José Mujica (Uruguay), with the establishment of a joint coordination of the activities in the river.
After twenty years of forest industry development, in October 2003, the Spanish company ENCE, received permission from the Uruguayan government to build a pulp mill in Fray Bentos, on the Uruguay River (which forms the natural border north between Brazil and Argentina and in the south between Uruguay and Argentina).
Argentinians residing mainly in Gualeguaychú, Entre Ríos, about 35 km from Fray Bentos, had been claiming that ENCE's pulp mill would pollute the river. Also, some demonstrations had been organized against ENCE.
After ENCE received its permit, another company, the Finnish Botnia, made public their intention to consider the same area for another pulp mill. Botnia received the environmental authorization to build a mill in February 2005.