ABSTRACT
The regional organizations, or more free groupings of states having a more or less institutional nature, represent a significant part of institutionalism in international law. Various regional groupings continued to develop also at the beginning of the 20th century. The period after the Second World War brought stronger treaties and an institutional understanding of regionalism together with the development of general international law. An important area being discussed after the Second World War concerned the role of regionalism within the area of international peace and security which was meant to be guaranteed by the collective sanction system of the UN Charter. With regards to the dramatic entry of regionalism into the international community in the second half of the 20th century, there were debates over the impact it had on the Westphalian system of the international community.
