  We show that from analysis of time-ordered diagrams for the two-nucleon
$T$-matrix in chiral perturbation theory it follows that low energy nucleon
dynamics is governed by the generalized dynamical equation, which was derived
in [J.Phys.A., v.32, p.5657 (1999)], with a nonlocal-in-time interaction
operator. An operator is presented that parametrizes the nucleon-nucleon
interaction in the 1S0 channel at leading order of the Weinberg power counting.
