  In first-quantized string theory, spacetime symmetries are described by inner
automorphisms of the underlying conformal field theory. In this paper we use
this approach to illustrate the Higgs effect in string theory. We consider
string propagation on M^{24,1} \times S^1, where the circle has radius R, and
study SU(2) symmetry breaking as R moves away from its critical value. We find
a gauge-covariant equation of motion for the broken-symmetry gauge bosons and
the would-be Goldstone bosons. We show that the Goldstone bosons can be
eliminated by an appropriate gauge transformation. In this unitary gauge, the
Goldstone bosons become the longitudinal components of massive gauge bosons.
