The main aim of this article is to provide a more solid theoretical anchor for numerous past and present debates about the various versions of American missile defence in Europe. The author claims that the neo-realism's concept of alliance security dilemma is the most appropriate framework for Czech, Polish, Romanian, and EU-wide experts'reflections and political decisions regarding the possible accepting of elements of American or NATO missile defence.
Under appreciated explanatory power of the concept of the alliance's security dilemma is illustrated in the text on the case of the original Bush's plan of the so-called third pillar in Poland and the Czech Republic.