Question

A few days ago it was reported in the press that, following information about the presence of a hostage in a certain area of the Gaza Strip, the IDF refrained from maneuvering there, which according to the report allowed Hamas terrorists to use it as a safe haven and launch attacks from it, in which 12 soldiers were ultimately killed.
In my view, adopting such a method is immoral.
At the same time, I tried to think about how I would view a military operation that would have been carried out in an attempt to rescue that same hostage, and that had gone wrong, and in which those same 12 soldiers would also have been killed—and here my position specifically tends toward seeing it as a moral action (of course not if, when setting out on the operation, there had been a high probability of such an outcome).
I am trying to think what the more “basic” positions are—ones that perhaps I am unable to formulate explicitly—that might lead to the difference between the two situations. After all, in both cases we are talking about taking some risk of losing soldiers’ lives in order to save a hostage.
Does the Rabbi happen to share those same moral intuitions in light of the two situations described, the real one and the hypothetical one? Whether yes or no, could the Rabbi suggest general lines for distinguishing between the two cases?
At the moment, the most “promising” direction I have arrived at is that in the rescue attempt there is some advancement of the war’s objectives beyond the rescue itself, whereas in the other situation that is not the case. But I am not sure that this is a convincing explanation, and that is why I am asking.
Thank you very much