  We examine the two-lead Kondo model for a d.c. biased quantum dot in the
Coulomb blockade regime. From perturbative calculations of the magnetic
susceptibility, we show that the problem retains its strong-coupling nature,
even at bias voltages larger than the equilibrium Kondo temperature. We give a
speculative discussion of the nature of the renormalization group flows and the
strong-coupling state that emerges at large voltage bias.
