We study the N=1 supersymmetric cascading gauge theory found in type IIB
string theory on p regular and M fractional D3-branes at the tip of the
conifold, using the T-dual type IIA description. We reproduce the
supersymmetric vacuum structure of this theory, and show that the IIA analog of
the non-supersymmetric state found by Kachru, Pearson and Verlinde in the IIB
description is metastable in string theory, but the barrier for tunneling to
the supersymmetric vacuum goes to infinity in the field theory limit. We also
comment on the N=2 supersymmetric gauge theory corresponding to regular and
fractional D3-branes on a near-singular K3, and clarify the origin of the
cascade in this theory.Comment: 43 pages, 18 figures, harvma