  QED perturbation theory in a background field has been conjectured to break
down for sufficiently high field intensity. The high-intensity behavior of a
field theory is however intertwined with its high-energy (UV) behavior. Here we
show that a UV modification of QED changes the high-intensity behaviour of
observables. Specifically we study non-linear Compton scattering in a constant
crossed field in QED with an additional Pauli term. In the UV modified theory
the cross section exhibits a faster power-law scaling with intensity than in
ordinary QED.
