Casus Belli: NATO Enlargement to Eastern Europe as a Justification for Russian Aggression to Ukraine

Casus Belli: NATO Enlargement to Eastern Europe as a Justification for Russian Aggression to Ukraine Russia claims that the Ukraine crisis stemmed from NATO enlargement to Russia's neighbouring countries. The idea is that the United States and its Allies had broken a promise not to expand NATO and the European Union in Central and Eastern Europe, as stated by Russian President Putin at the Munich Security Conference in 2007. However, more interestingly, since the mid-1990s the debate on NATO expansion as a threat to Russia often resurfaces in Western political thought in periods of crisis with Russia. This article will uncover, by examining the historical events and documents, that there was never such a promise not to expand NATO, while the only existing promise made by NATO was not to deploy nuclear weapons in Central and Eastern Europe. Keywords: Russia, NATO, European Union Enlargement, Cold War, NATO-Russia negotiations