Predictions for processes preparatory to earthquakes based on an inclusion model of faulting are reviewed. The inclusion material is assumed to have properties representative of the response of brittle rock in compression; specifically, the inelastic response is strain softening, inhibited by hydrostatic compression and exhibits volume increase (dilation) due to shear. Strain softening of the inclusion material leads to a dynamic runaway of inclusion shear strain which is interpreted as the occurrence of an earthquake. For both dry and fluid-saturated rock masses, the model predicts that runaway instability is preceded by a period during which the rate of inclusion strain accelerates relative to the far-field strain rate. However, in a fluid-infiltrated rock mass, the coupling of the deformation with pore fluid diffusion causes a much more pronounced period of accelerating inclusion strain and delays the onset of instability beyond its occurrence in a dry rock mass. This transient stabilization arises from two mechanisms: the time dependent elastic response of the fluid-infiltrated material surrounding the inclusion and the dilatant hardening of the inelastic response of the inclusion material. The results for stabilization by dilatant hardening are shown to be consistent with recent laboratory experiments. The analysis is based on generalizations of Eshelby's results for inclusions to nonlinearly deforming inclusions and to a spherical inclusion embedded in a linear fluid-infiltrated elastic solid. , k, k