  It is shown how the deformation of the superconformal generators on the
string's worldsheet by a nonabelian super-Wilson line gives rise to a covariant
exterior derivative on loop space coming from a nonabelian 2-form on target
space. The expression obtained this way is new in the context of strings, and
its consistency is verified by checking that its global gauge transformations
on loop space imply the familiar gauge transformations on target space. We
derive the second order gauge transformation from infinitesimal local gauge
transformations on loop space and find that a consistent picture is obtained
only when the sum of the 2-form and the 1-form field strengths vanish. The same
condition has recently been derived from 2-group gauge theory reasoning. We
observe that this condition implies that the connection on loop space is flat,
which is a crucial sufficient condition for the nonabelian surface holonomy
induced by it to be well defined. Finally we compute the background equations
of motion of the nonabelian 2-form by canceling divergences in the deformed
boundary state.
