This work is a translation of the German edition "Der Nukleonenspin als Ursache der starken Wechselwirkung". (Dec. 2020). The strong interaction is supposed to describe the forces which are active in the atomic nucleus between the nuclear building blocks. Until today, however, it has not been possible to design a theory free of contradictions. Instead, in the 1970s, the theory of "quantum chromodynamics" emerged, in which the name itself is based on an analogy. Just like the "color charges" mentioned as cause of the interaction. The question is only: Analogy to what and due to which energy? Because either it refers to the electric energy, then there would have to be some kind of electric parallel energy, but this is nonsensical. Or it doesn't refer to the electric energy, then it must be a form of energy which already exists. But quantum chromodynamics makes no statement about this. This QCD theory standing on shaky feet thus virtually challenges the contradiction. In order to oppose this very artificial theory with a down-to-earth one, it is important to keep in mind the basics of the known interactions. All particle systems can build up only if their particles have besides their energy also an opposite property by which they can interact. The simplest system is a binary system, e.g. a common salt crystal. The opposite properties are the electrically positive and negative charge of the ions. But which opposite property enables an interaction of the nucleons? It cannot be an electric charge. The astonishing answer to this question is given in this paper at the end. It also becomes clear that quantum chromodynamics is a fallacy. For a better understanding, contents of earlier publications of the author are partly included.