  We generalize the (2+1)-dimensional Yang-Mills theory to an anisotropic form
with two gauge coupling constants $e$ and $e^{\prime}$. In an axial gauge, a
regularized version of the Hamiltonian of this gauge theory is
$H_{0}+{e^{\prime}}^{2}H_{1}$, where $H_{0}$ is the Hamiltonian of a set of
(1+1)-dimensional principal chiral nonlinear sigma models. We treat $H_{1}$ as
the interaction Hamiltonian. For gauge group SU(2), we use form factors of the
currents of the principal chiral sigma models to compute the string tension for
small $e^{\prime}$, after reviewing exact S-matrix and form-factor methods. In
the anisotropic regime, the dependence of the string tension on the coupling
constant is not in accord with generally-accepted dimensional arguments.
