  We study a class of dilatonic deformations of asymptotically AdS_5 X S^5
geometry analytically and numerically. The spacetime is non-supersymmetric and
suffers from a naked singularity. We propose that the causality bound may serve
as a criterion for such a geometry with a naked singularity to still make sense
in the AdS/CFT correspondence. We show that the static string, the one
corresponding to a large Wilson loop in the dual gauge theory, reveals
confinement in a certain range of parameters of our solutions, where the
singularity exhibits the repulsion that can well cloak the singularity from the
static string probe. In particular, we find the exact expression for the
tension of the QCD strings. We also discuss a possible interpretation of our
solution in terms of unstable branes and their tachyon matter.
