Fast cooling of muon beams will be needed for building either TeV muon coll
iders that might explore the electroweak gauge symmetry breaking or muon st
orage rings that could become ultrabright neutrino soul ces. Stochastic and
electron cooling take longer than the muon lifetime, so attention has been
focused on the potentially faster but less explored ionization cooling. Ad
dressing recent concerns that excitation of Langmuir waves might be deleter
ious for ionization cooling techniques, we show that, while the hydrodynami
c instability indeed might be dangerous, the waves are, in fact, stabilized
through a combination of resistive and kinetic effects at a very modest em
ittance of the beam.