The history of strong-interaction theory in the 1950s is one of a continuous struggle to bring the tradition handed down from the dead generations into conformity with contemporary needs. The tradition was quantum field theory (QFT), and the need was to confront the masses of data on strong-interaction processes emerging from the growing number of high-energy particle accelerators. The struggle originated in the observation that the strong interactions were indeed strong: The pion–nucleon coupling constant, for example, could be estimated to be appreciably greater than unity. The perturbative methods developed in the late 1940s for applications of renormalized quantum electrodynamics therefore failed when applied to the strong interaction. As Steven Weinberg put it in his 1977 Notes for a History of Quantum Field Theory, “it was not that there was any difficulty in thinking of renormalizable quantum field theories that might account for the strong interactions – it was just that having thought of such a theory, there was no way to use it to derive reliable quantitative predictions, and to test if it were true.”

Weinberg proceeded from this observation to remark that “the uselessness of the field theory of strong interactions led in the early 1950s to a widespread disenchantment with quantum field theory” that lasted for almost twenty years.