The Gabčikovo-Nagymaros Project is not just a dispute between Hungary and Slovakia. It had political and historical consequences before, during and after the regime change. Firstly, the complexity of prior events – which led to the escalation of the debate – is outlined. Thus, it is unavoidable to understand the concerns and claims of the parties. Then, the questions submitted to the International Court of Justice and the given answers are analysed while also pointing out the legal consequences of the Judgement.In conclusion, the factors are summarized, answering why it is still an unresolved international dispute.