The immigrating Aryans had not encountered mighty enemies and big empires--such as in Persia. Thus they were not forced by events to develop political units which would allow for more effective military capacity, to seize and protect territory--as did the Aryans in Persia, where they developed imperial organization early. On the contrary, the proliferation of little kingdoms, the janapada, in the western Genges Valley was a political luxury which the Aryans could afford; they could afford to remain decentralized. Thapar argues that this luxury arrested political development in north India--state formation took place at a slow rate. The integration of society and internal harmony was sought, not through political administration, but through the varna structure. The latter was a successful mechanism for incorporating a diversity of ethnic and cultural groups where each group maintained a separate identity in relationship to other groups, in caste organization. Land was plenty in the Vedic Age and the socio-political system could reproduce itself through fission rather than undergo a change of form to meet a need for further
resources or to meet the pressure of new numbers. Furthermore, land in the Western Gangetic Valley was cultivable without major cooperative organization.