The husband just posed the question to me, was Dumbledore cruel to use Snape as he does in the books?
I say not really. Manipulative in the extreme yes, but not cruel and here is why.
Snape was a death eater all the way until the moment Voldemort killed Lilly. At that moment it was a switch. Voldemort had done the one thing he could not overlook and forgive. Hell hath no fury like a woman scorned is the saying but killing a one ture love is pretty damn close. From that moment on Snape was filled with hatred and a desire to destroy Voldy. Unfortunately he was dead right? So Snap got to go on being his bitter, nasty, thwarted self.
Dumbledore and his people always knew there was a possibility that Voldy would be back. Dumbledore used this belief and Snapes hatred to keep him close. It was also how Dumbledore could be 100% sure that Snape was his man.
Joining with Dumbledore preserved Snapes life. Without the guidance of the plan and his vow to Dumbledore, Snape would most likely have followed his hatred and foolishly went up against Voldy much sooner and would have lost. Dumbledore helped keep him on track and to understand that someone else had to destroy Voldy.
I also would argue that it was Snapes vow to Dumbledore that allows him to make the unbreakable vow to help and protect Draco. I think his personal hatred would have prevented him from doing so. Dumbledore knew that it was necessary to save Draco from being permanently lost to the darkness and to get Snape fully inside again and to get people where they needed to be for the final showdown to come.
Thoughts?