  Scattering processes in laser backgrounds are degenerate to the emission of
unobservable photons collinear with the laser. We identify processes and
observables for which such degeneracies factorise and exponentiate, obtaining
the leading-order intensity dependence of these inclusive observables at high
laser intensity, correct to all orders in the fine-structure constant (all
loops, all emissions). The results show an exponential intensity dependence
distinct from that predicted by the Narozhny-Ritus conjecture on the
high-intensity behaviour of quantum electrodynamics in strong fields.
