Private international law plays a key role in regulating and resolving conflicts of jurisdiction between states. Each state clings to the principle of sovereignty - which has recently begun to decline - and which has expanded from territorial jurisdiction according to the principle of territoriality, to imposing jurisdiction and sovereignty over the citizens of the state according to the principle of personality, both positive and negative. It is realistic to notice the actual advantage enjoyed by the territorial state, where it reserves the accused, evidence, witnesses, and complete actual control. This makes it difficult to transfer witnesses and evidence to the prosecuting state, which adopts the prosecution for any reason and according to any principle other than the principle of territoriality. The principle of universality, or integrative universal jurisdiction, is not an exception, where priority is always given to the application of the principle of territoriality. However, the principle of universality came to bridge the legal gap and loophole due to the intertwining of judicial jurisdictions and their conflicts, which were revealed by the practical reality with the proliferation of piracy crimes in the high seas. The research seeks to examine the effectiveness of the principle of universal jurisdiction for national criminal courts, especially in light of the development of criminal crimes, particularly cybercrimes