For a variety of reasons, including U.S. Federal law and improved safety, it is desirable to have insensitive munitions (IM). Although a variety of methods are available to reduce the sensitivity of munitions only changes to the high explosive (HE) itself result in increased safety during storage, transportation, handling, and deployment. As a result of this IM are almost always filled with fire resistant, shock resistant insensitive HE such as triaminotrinitrobenzene (TATB). The high cost of TATB has limited its use. In this study we examine 28 nitro-aromatics, including TATB and five previously unpublished structures, in the solid state in order to identify forces that stabilize the HE. We show that the sum of forces involved in crystal packing (i.e. the estimated energy of stabilization) has a direct relationship to the observed sensitivity of nitro-aromatic explosives.