  The exact Seiberg-Witten (SW) description of the light sector in the $N=2$
SUSY $4d$ Yang-Mills theory is reformulated in terms of integrable systems and
appears to be a Gurevich-Pitaevsky (GP) solution to the elliptic Whitham
equations. We consider this as an implication that dynamical mechanism behind
the SW solution is related to integrable systems on the moduli space of
instantons. We emphasize the role of the Whitham theory as a possible
substitute of the renormalization-group approach to the construction of
low-energy effective actions.
