[en] The question of whether polarized beams of 12 GeV or, preferably, higher energy can be produced at other existing or planned accelerators is explored. Sources of polarized H^- ions suitable for injection into accelerators appear to be feasible with intensities in the milliampere range (an order of magnitude better than present performance at Argonne). This would be sufficient to produce polarized beams of intensities comparable (though somewhat weaker) to those of unpolarized beams in high energy accelerators and luminosities not more than a factor of about 10 lower than those for unpolarized beams in storage rings, such as the CERN ISR or ISABELLE, the 400 GeV storage accelerator system now under design at BNL. The major question, then, is whether it is possible to maintain polarization in these accelerators during the acceleration process and during storage in a storage ring