Opportunity Cost is Everywhere: The Ethics of Search and Rescue

An outstanding post (hat tip Texas in Africa) considering what is gained and sacrificed for landing more search and rescue personnel on the ground. The basic math is that we send in 1700 S&R, who can only get there 1-2 days after the disaster so they have very little time left to find people, thousands have already been saved by locals, and we pull out another 90. Or we could send in more medical personnel to help everyone else. It's about lives saved, not money spent, and there's no attempt to try to monetize human life. Could we save more people and relieve more suffering doing something else?

One commenter makes an extremely cogent point in the other direction. After pointing out the importance of outside help to relieve exhausted local S&R, this ethical plea:

There is also an emotional necessity to bringing in more S&R, even when other types of aide are desperately needed. How well could other aide workers function, if they knew that people were trapped, local rescuers exhausted to collapse, and no one is left to do the last of the “digging out”? For both local and foreign aide workers, the decision to leave trapped people to die so that the effort can be made to help in other ways would be a difficult one. Knowing that the S&R is continuing eliminates that distraction.

I wonder for how many other disease or development related projects this is also the case? I can focus on hunger, comforted that someone else is handling malaria, who is in turn comforted by knowing I'm trying to get them fed. Is this a positive externality? Are different interventions complementary? Would you dare propose a study that could experimentally demonstrate it?