  Theories with approximate no-scale structure, such as the Large Volume
Scenario, have a distinctive hierarchy of multiple mass scales in between TeV
gaugino masses and the Planck scale, which we call SUSY's Ladder. This is a
particular realization of Split Supersymmetry in which the same small parameter
suppresses gaugino masses relative to scalar soft masses, scalar soft masses
relative to the gravitino mass, and the UV cutoff or string scale relative to
the Planck scale. This scenario has many phenomenologically interesting
properties, and can avoid dangers including the gravitino problem, flavor
problems, and the moduli-induced LSP problem that plague other supersymmetric
theories. We study SUSY's Ladder using a superspace formalism that makes the
mysterious cancelations in previous computations manifest. This opens the
possibility of a consistent effective field theory understanding of the
phenomenology of these scenarios, based on power-counting in the small ratio of
string to Planck scales. We also show that four-dimensional theories with
approximate no-scale structure enforced by a single volume modulus arise only
from two special higher-dimensional theories: five-dimensional supergravity and
ten-dimensional type IIB supergravity. This gives a phenomenological argument
in favor of ten dimensional ultraviolet physics which is different from
standard arguments based on the consistency of superstring theory.
