The problem of the growth of a crack located at the interface between two linearly elastic solids is considered when conditions promoting propagation along and/or away from the interface prevail. Both a stress and a maximum energy release rate criterion are examined. It is found that in contrast to the corresponding problem for crack growth in homogeneous solids, no unique propagation direction results when continuum considerations prevail alone. Uniqueness is established only upon invoking a presumably material dictated minimum crack extension size. The result for this linearized analysis are compared with experimental observations on kink fracture involving two elastomers of small strain capabilities.