  We revisit the stabilization of ionization of atoms subjected to a
superintense laser pulse using nonlinear dynamics. We provide an explanation
for the lack of complete ionization at high intensity and for the decrease of
the ionization probability as intensity is increased. We investigate the role
of each part of the laser pulse (ramp-up, plateau, ramp-down) in this process.
We emphasize the role of the choice for the ionization criterion, energy versus
distance criterion.
