't Hooft loop in SU(2) lattice gauge theories

We examine the behavior of the 't Hooft loop (magnetic disorder parameter) for weak coupling ($\beta \to \infty$) in the standard SU(2) lattice gauge theory. We find that it exhibits length-law falloff due to the presence of dynamical $Z_2$ monopoles. These dynamical monopoles are a consequence of the nonconservation of $Z_2$ flux, and the possibility of flux spreading in the non-Abelian theory. The implications for quark confinement are discussed.