  We explain how a vanishing, or truncated, perturbative expansion, such as
often arises in semi-classically tractable supersymmetric theories, can
nevertheless be related to fluctuations about non-perturbative sectors via
resurgence. We also demonstrate that, in the same class of theories, the
vanishing of the ground state energy (unbroken supersymmetry) can be attributed
to the cancellation between a real saddle and a complex saddle (with hidden
topological angle pi), and positivity of the ground state energy (broken
supersymmetry) can be interpreted as the dominance of complex saddles. In
either case, despite the fact that the ground state energy is zero to all
orders in perturbation theory, all orders of fluctuations around
non-perturbative saddles are encoded in the perturbative E(N, g). We illustrate
these ideas with examples from supersymmetric quantum mechanics and quantum
field theory.
