  The infrared behaviour of the ${\phi}^3$-theory is discussed stressing
analogies with the Witten-Seiberg story about $N=2$ $QCD$. Though the
microscopic theory is apparently not integrable, the effective theory is shown
to be integrable at classical level, and a general solution of it in terms of
hypergeometric functions is obtained. An effective theory for the multiparticle
soft scattering is sketched.
