  The phenomenon known as ``anomaly mediation" can be understood in a variety
of ways. Rather than an anomaly, certain gaugino bilinear terms are required by
local supersymmetry and gauge invariance (the derivation of these terms is in
some cases related to anomalies in scale invariance or $R$ symmetries). We
explain why the gaugino bilinear is required in supersymmetric gauge theories
with varying number of colors and flavors. By working in the Higgs phase,
gauging a flavor group, or working below the scale of gaugino condensation,
each of these theories has a local effective description in which we can
identify the bilinear term, establishing its necessity in the microscopic
theory. For example, in theories that exhibit gaugino condensation, the
potential in the very low energy theory is supersymmetric precisely due to the
relation between the nonperturbative superpotential and the gaugino bilinear
terms. Similarly, the gravitino mass appears from its coupling to the gaugino
bilinear.
