Will Walsh got to know the Iraqi city of Fallujah while running across its bridges in the middle of the night, under fire, looking for IEDs. That was nearly 10 years ago.
Last weekend, the former Army captain heard the news that Fallujah had fallen, again, to al-Qaida-linked groups.
"The question I have to ask myself is was that effort in vain?" he says now. "Was all the work that we did, all the sacrifice that we had, what is the benefit?"