This essay refers to the federalist theoretical paradigm and especially to its view of inter-national relations. This paradigm takes inspiration from the theory of political realism, with the aim to overcome it, drawing on the political thought of Immanuel Kant. On this basis it is proposed a vision of the current world order crisis, which is characterized by existential chal-lenges on multiple plans concerning security, the socio-economic situation, and the environ-ment. The answer to this crisis is identified in a substantial progress towards world unification, with respect to which a fully fledged European Federation (which is on the political agenda) is called to play a leading role.