  We investigate the weak decay of uniformly {\em accelerated protons} in the
context of {\em standard} Quantum Field Theory. Because the mean {\em proper}
lifetime of a particle is a scalar, the same value for this observable must be
obtained in the inertial and coaccelerated frames. We are only able to achieve
this equality by considering the Fulling-Davies-Unruh effect. This reflects the
fact that the Fulling-Davies-Unruh effect is mandatory for the consistency of
Quantum Field Theory. There is no question about its existence provided one
accepts the validity of standard Quantum Field Theory in flat spacetime.
