We have investigated the photodissociation of HCO+ in a strong field with a wavelength of 10 mu m using ab initio molecular dynamics. Classical trajectories were calculated at three field intensities. At 2.9 x 10(14) W/cm(2) and phase phi = 0, protons have two distinct dissociation times, mainly due to the reorientation of HCO+ relative to the field direction prior to dissociation. The kinetic energy distribution at this intensity agrees with Wardlaw's wagging tail model, suggesting that dissociation occurs through barrier-suppression. At 1.7 x 10(14) and 8.8 x 10(13) W/cm(2), barrier suppression is incomplete and the maximum kinetic energy is less than predicted by the wagging tail model. (C) 2012 Elsevier B. V. All rights reserved.