This book presents the execution of international policies normally used by States which, as has been seen, carry with them a realpolitik, this being understood as a policy or diplomacy based on practical interests and concrete actions, without paying attention to theory or philosophy as "policy-forming" elements. This paper in no way intends to approach the issue of collective security from a theoretical perspective, but rather from an operational viewpoint, taking into account the development of political actors and career diplomats in the global sphere of international relations and collective security, which is why their actions are more strongly focused on practical procedures and actions, whose conduct is adjusted to reality, putting pragmatism before theory.