Unread postby MantisFA » March 11th, 2015, 1:09 am
Nurmengard apparently held Grindelwald for over forty years without using Dementors as guards, so the necessity of Dementors in a prison intended to hold wizards and ensure they don't escape is questionable at best. In the face of a powerful force operating outside the prison and determined to free its imprisoned allies, however, execution of those allies may indeed be the only sure way to prevent that force from overwhelming the prison's guards and increasing its strength thereby. Immediate execution seems far more human than a life sentence under the soul-crushing influence of the Dementors in any case.
It was implied, but never stated in canon, that one reason the Dementors were used to guard Azkaban was that they were impossible to destroy, so the Ministry needed to make some kind of deal with them to keep them from making trouble; Voldemort, of course, was able to offer them a more attractive deal, with far more opportunities to eat people's souls outright (i.e. Kiss them) instead of just nibbling on them, so they defected to his side and released the Lestranges, Dolohov, and the rest of the surviving Death Eaters imprisoned after the first war. In this story, it's been established (contra canon) that Dementors can be destroyed by forcing them against the latest model anti-Dementor wards with something as simple and ubiquitous as a Summoning Charm. The obvious conclusion is that if at all possible, the Dementors in Azkaban should be exterminated by erecting such wards around the prison and summoning the Dementors into them, before those Dementors become a powerful addition to Voldemort's faction.
I'm interested to see what will happen in NoFP when Harry meets Mad-Eye Moody. Moody is a veteran of the first war, nearly as deadly a combatant as Dumbledore, and far more ruthlessly pragmatic than Dumbledore ever was; in the earlier timeline, he led the defense of Azkaban before it finally fell to Voldemort, and made certain that no imprisoned Death Eaters survived to rejoin their master when that happened. If he could be trusted with Harry's secret, he might have sufficient connections from his Auror days to ensure that Bellatrix et. al. never leave Azkaban alive in the new timeline.