Updating the Unitarity Triangle: Top Quark Mass Versus Nonperturbative Uncertainties

We summarize the present knowledge on the non-perturbative hadronic inputs needed in the analysis of $B^0$-${\bar{B}}^0$ mixing and the CP-violating parameter $\epsilon$ of the $K^0$-${\bar{K}}^0$ system. Using this information, together with the recently determined value of the top-quark mass, we update the phenomenological constraints on the unitarity triangle.