International law, it is in fact, a system. However, it is a complex one, an ’emergent’ phenomenon. This means that it is created from the interaction of agents, being those agents: states and certain non-state actors. International law as a complex system has the characteristic of being radically open, without the possibility to draw a definite line as to where the boundary can be placed.
Such radical openness of the system may confuse scholars. Why? Well because there could be said that international law is merging with municipal systems. However, municipal legal systems can also be understood as complex systems. This means that the radical openness of the systems may cause the mirage of merging of systems. However, they remain separate, although the boundaries are fuzzy.
Do systems merge or integrate? Maybe up to a certain point, depending how open or closed a system is.
Derecho Internacional y otras ilusiones 