  Confirming a conjecture of Lyng--Raoofi--Texier--Zumbrun, we show that
stability of strong detonation waves in the ZND, or small-viscosity, limit is
equivalent to stability of the limiting ZND detonation together with stability
of the viscous profile associated with the component Neumann shock. More, on
bounded frequencies the nonstable eigenvalues of the viscous detonation wave
converge to those of the limiting ZND detonation, while on frequencies of order
one over viscosity, they converge to one over viscosity times thos of the
associated viscous Neumann shock. This yields immediately a number of examples
of instability and Hopf bifurcation of reacting Navier--Stokes detonations
through the extensive numerical studies of ZND stability in the detonation
literature.
