[PKop]

attempting to argue that returning a kidnapped child to their parents may NOT be regarded as a success because of the "cost of the initiative" is morally indefensible.

You're saying that any and all possible attempts at finding / returning a child would have zero costs associated, or that whatever the negative cost is irrelevant and should be disregarded. Imagine the government shifts a massive amount of spending towards finding missing children, and suspends the 4th amendment, hires a massive army of investigators and searches door to door to find missing children. Of course this is an exaggerated scenario but it's at least arguable that the negative costs associated with this plan could outweigh the benefits, and that this would be morally undesirable. I don't think there is ever a scenario where costs can be completely ignored / discounted to obtain any amount of beneficial outcome. If you agree with my point in the extreme case, but not in the original scenario, then the disagreement is one of degree not principle. i.e. "well it depends on the costs.." Exactly.

[nl]

I'm saying that if your "exaggerated scenario" reunited a child with their parents it would be a success. I'm not arguing that something like that should be done, nor am I arguing that cost effectiveness cannot be considered.

I am saying that given that the prior condition of successfully reuniting a child with their parent then saying it was not successful because it cost too much is putting a price on the child's life. That is morally repugnant in this circumstance.

[user24]

We're just dealing with two different definitions of success here aren't we?

Success Definition One: Success occurs when the child is returned. This is a binary outcome and you're right to say that if the child is returned then it simply is a success under this definition and nothing can change that.

Success Definition Two: The scheme works and is practical. This is a qualitative outcome which does require comparing apples to oranges (or as you emotively put it; "putting a price on a child's life"). If Bill Gates offered 12 billion dollars for the return of a child, no questions asked, no law enforcement involved, it might work very well indeed, but cannot be called a success under this definition.

With regard to the 'prior condition', I would still argue that if the scenario under Two above occurred, and worked, I would still call it a failure under definition two and a success under definition one.

And honestly, definition two is the more interesting one to try to produce a solution for.