The fraction &Dgr; of warm plasma needed to stabilize the drift cone mode is calculated for a loss cone plasma slab in a uniform magnetic field withRp∼aH∼k−1, whereRpis the width of the slab (representing the radial scale length),aHis the hot ion Larmor radius, andkis the wavenumber of the mode. For 2XIIB‐like parameters, a minimum &Dgr; of 14% is needed for stability, which is consistent with experimental observations. This result is an improvement on previous calculations, which used the local approximation (assumingRp≫aH≫k−1) and gave a minimum &Dgr; of 10% for the same parameters. Information is also obtained on the radial location and width of the normal modes, and on the effect of varying the warm plasma radial density profile.