Recent studies of the lower hybrid drift instability have shed new light on the role of this mode in field reversed plasmas. For substorm magnetotail conditions we find that the lower hybrid drift instability can penetrate to the neutral line and can dissipate magnetic energy at a rate WB?4¿1017 erg/s. Thus this instability is capable of playing a major role in the onset of substorms and providing resistivity for reconnection processes in the context of the neutral line substorm model.