  We provide a resolution of one of the long-standing puzzles in the theory of
disordered systems. By reformulating the functional renormalization group (FRG)
for the critical behavior of the random field Ising model in a superfield
formalism, we are able to follow the associated supersymmetry and its
spontaneous breaking along the FRG flow. Breaking is shown to occur below a
critical dimension $d_{DR}\simeq 5.1$ and leads to a breakdown of the
"dimensional reduction" property. We compute the critical exponents as a
function of dimension and give evidence that scaling is described by three
independent exponents.
