Lattice regularization and confinement at strong coupling   back  
In 1974 Wilson proposed an approach to QCD that opened a new era. He suggested to use a discrete spacetime as a regulator of the theory in the Euclidean path integral formalism, and showed how the regularisation can preserve local gauge invariance. One virtue of this approach is that it exposes the inverse of the coupling constant as a natural expansion parameter, making it possible to access the non-perturbative regime of the theory analytically. In this way, it is possible to prove that the theory confines at strong coupling.

References:
  • K. Wilson, Phys Rev. D10, 2445 (1974)
  • I. Montvay, G. Muenster, Quantum Fields on a Lattice, Cambridge University Press, 1997. sects 3.1-6.