Snape's dirty past uncovered/UK vs. US

[justcarol67]

No: HPFGUIDX 170513

Carol earlier:
> > Carol, who thinks that Snape's DE past *was* a secret, otherwise 
> the
> > exposure of it would not have deterred DD from giving him the DADA
> > post for so long
> 
> Magpie:
> Wait, I didn't understand this last part. Are you saying that 
> Dumbledore didn't give Snape the DADA position until HBP because it 
> would expose his DE past?

Carol again:

In a word, yes, but that's only part of it. If the DADA curse exposes
the faults or secrets of the DADA teacher, then it will act on
something related to Snape's DE past. Rather than causing him to fall
back into his "old ways" (infatuation with Dark magic or supposed
loyalty to Voldemort), which I think is Snape's and DD's cover story,
the curse would reveal him as a DE, apparently loyal to Voldemort. And
I think that, despite Snape's obvious qualifications for the post and
real or supposed desire to teach that class, Dumbledore wanted to have
him around as long as possible.

But once Voldemort had returned and was no longer distracted by the
Prophecy orb, Dumbledore couldn't, IMO, afford to wait any longer. He
needed Snape as DADA teacher (including the side job of dealing with
any Dark magic that made its way into Hogwarts) more than he needed
him as Potions master. Conditions conspired to make HBP Snape's DADA
year: Voldemort's return to power and the consequent need for Snape's
expertise while there was still time, no other qualified applicants
and the danger of another Ministry-approved teacher if DD didn't hire
Snape, Draco's mission, Dumbledore's Horcrux injury, Harry's
approaching coming-of-age, the need to bring Slughorn (who just
happened to be qualified to teach Snape's old subject and take his
place as HOH after the curse struck) to Hogwarts, the need to send
Snape under cover as a DE at the end of the year (which, I'm sure, is
the form they both expected the curse to take). His exposure as a DE
(which would, they perhaps hoped, force DD to fire him) would enable
him to pretend to be loyal to Voldemort while secretly spying for the
Order. Unfortunately for them both, the UV (IMO, a manisfestation of
the DADA curse) got in the way and spoiled their plan.

I know I've mentioned all this before, but I realize that it's hard to
keep track of everyone's views, so youve probably forgotten. :-) But,
again, yes--I think that both Snape and DD expected the DADA curse to
take the form of Snape's exposure as a "loyal" DE, which would cause
him to be fired. Once the UV was in place, they probably feared
something much worse, but, by then, it was too late to change their
plan. (I'm not talking about a plan to fake DD's death, only a plan to
send Snape undercover at the end of his year as DADA teacher.) But
that Dumbledore waited to give Snape the DADA position until it was
absolutely necessary, or until the time was right, as you prefer,
seems to me crystal clear.

Carol, who thinks that, as usual, Dumbledore had more than one reason
for his action, and in this case, it's hard to say which was the main one