  We use the `branes within branes' approach to study the appearance of stable
$ (p-2)-branes and unstable (p-1)-branes in type II string theory from
p-brane--p-antibrane pairs.Our goal is to describe the emergence of these lower
dimensional branes from brane-antibrane pairs in string theory using a
tractable gauge theory language. This is achieved by suspending the original
p-brane--p-antibrane pair between two (p+2)-branes, and describing its dynamics
in terms of the worldvolume gauge theory on the spectator (p+2)-branes.
Instantons, monopoles, sphalerons and their higher-dimensional generalizations
in this worldvolume gauge theory correspond to stable (BPS) and unstable
(non-BPS) branes in string theory. Collisions of stable branes with
corresponding antibranes and production of lower-dimensional branes in string
theory are described in a straightforward way in gauge theory. Tachyonic modes
on the p-brane--p-antibrane worldvolume do not appear in our analysis since we
work on the worldvolume of the spectator (p+2)-branes. Our results on brane
descent relations are in agreement with Sen's tachyon condensation approach.
