wallerstein's work developed at a time when the dominant approach to understanding development, modernization theory, was under attack from many front, and he followed suit.He himself acknowledges that his aim was to create an alternative explanation . He aimed at achieving "a clear conceptual break with theories of modernization and thus provide a new theoretical paradigm to guide our investigations of the emergence and development of capitalism, industrialism and national states. Criticisms to modenization include (1) the reification of the nation-state as the sole unit of analysis, (2)