  Anti-D3-branes at the tip of the Klebanov-Strassler solution with D3-charge
dissolved in fluxes give rise, in the probe approximation, to a metastable
state. The fully back-reacted smeared solution has singular three-form fluxes
in the IR, whose presence suggests a stringy resolution by brane polarization a
la Polchinski-Strassler. In this paper we show that there is no polarization
into anti-D5-branes wrapping the $S^2$ of the conifold at a finite radius. The
singularities therefore do not seem to be physical, signaling that antibranes
cannot be used to uplift AdS and obtain a very large landscape of de Sitter
vacua in string theory.
