There's a mental trap many people fall into where if you spend a lot of resources on something that fails, you want to keep spending more so that your losses weren't in vain. But the fact is that if something just is too expensive or hopeless, pouring more resources into it just isn't a good idea, no matter how much you have already spent. The Americans who died in Iraq died for nothing, and that can't be changed. Sending more Americans to their deaths won't somehow validate it. We screwed up going in there at all, we just need to accept it and stop sending our people to die.