National project and global solidarity [JOAN PRATS] This article maintains that in a global age the credibility of Catalonia as a nation demands the inclusion of a civic and political commitment for international solidarity in the catalan national construction agenda. Development, as the aim of international solidarity, must be understood as an evolutive social construction and as a public good with two dimensions: a global one referring to the international community and a national one that belongs to each beneficiary country; it is explicitly rejected any normative consideration of development as a public good of the donor countries. Globalization does not impede the presence of national and territorialized actors both in economic and in solidarity fluxes, althoug national actors are not pursuing their national interests but acting as members of the international community; territorialization and coordination between donors is considered as an important asset for the effectiveness of development aid. Finally, this article clarifies the real contribution of Catalonia to the whole Spanish public development aid, and presents some lessons from the international experience on the effectiveness of foreign aid, claiming for reforms both in the institutional frameworks and policies of donor countries and in the institutional, economic and environement policy of recipient countries.