The problem of Public International Law effectiveness has been continuously analyzed by international law legal scholars. Very useful approaches have already been identified and now a wide range of theories as to how to tackle this important issue can be pinned down: From those who believe in a “realistic approach,” to those who try to find in deep philosophical reasons the problem of effectiveness, all legal scholars try to explain why entities in the international arena should behave in a way that permits human beings to fulfill the divine (or Absolute) mandate: that of achieving their own happiness. The underlying idea of this paper might be explained by saying that we try to find an explication that satisfies at the same time, both the plane of “What it is” and the plane of “What ought to be or what should be (The “Must-Be” plane).” And in this sense, this paper which tries to do so by using a multidisciplinary approach (as we use not only the juridical sciences, but also HABERMAS’ “Social Philosophy,” the JACKSON’S International Economic Law approach and the political science as well as the political economy and the psychology), concludes that for Public International Law to exist, and in fact, it does exist, it has to be effective, and indeed it is. The problem is describing how it is effective; hence a conclusion is laid out in the sense that only a customary-time restrained and times-oriented/focused international law is that which is effective. That is what reality shows, so in a way this paper might fall down under the label of what legal scholars throughout the world have called the “realistic approach.”