[en] Alpha particle populations can significantly alter existing MHD instabilities in tokamaks through kinetic effects and coupling to otherwise stable shear Alfven waves. Here we consider resonances with the trapped alpha precessional drift. This is examined in the high-n ballooning limit using an isotropic alpha slowing down distribution and retaining the full energy and pitch angle dispersion in the alpha drift frequency. We also employ a noncircular tokamak equilibrium model. Applying this to ITER indicates that ballooning instabilities can persist at β's below the ideal MHD threshold. 12 refs., 2 figs