62 There are other obstacles to creation of a more just social order and to the development of world solidarity: nationalism and racism. It is quite natural that nations recently arrived at political independence should be quite jealous of their new-found but fragile unity and make every effort to preserve it. It is also quite natural for nations with a long-standing cultural tradition to be proud of their traditional heritage. But this commendable attitude should be further ennobled by love, a love for the whole family of man. Haughty pride in one's own nation disunites nations and poses obstacles to their true welfare. It is especially harmful where the weak state of the economy calls for a pooling of information, efforts and financial resources to implement programs of development and to increase commercial and cultural interchange. . . . and Racism
Source: Populorum Progressio (Vatican.va)