NATO expansion was, and is, necessary for international stability  Enlargement was necessary to prevent Europe “reverting to type”. The rise once again of the ethnic and religious causes of war. [1] And this is still a reason for NATO to expand to help stabilise Europe. The Balkans is only the worst area for Ethnic tensions; there are similar cases all over Eastern Europe and the former Soviet Union. The history of Eastern Europe has been one of empires not the nation state. Stalin had a policy of divide and rule; he made sure each soviet republic included substantial minorities in order to prevent the growth of nationalist movements. [2] Stalin only continued a long tradition of ethnic movements within empires in Eastern Europe. The Balkan problem for example is considered an effect of the Ottoman empire; hence the Christian/Moslem divides in Bosnia and Kosovo. The Austrian Empire settled people on its frontiers in much the same way; the result is that none of the eastern European states is ethnically homogeneous. The Violent break-up of Yugoslavia showed the way many other states could potentially go, NATO wished to avoid this and enlargement was its best solution.  [1] Coker, Christopher, ‘The Geopolitical Implications of the Expansion of Europe’ pp5-12 NATO looks east ed. Piotr Dutkiewicz and Robert J. Jackson (Westport, Praeger publishing, 1998) p.8  [2] Keylor, William R., The Twentieth Century World (Oxford, Oxford University Press, 2001), p.460