They died believing they did the right thing. Whether they died doing something YOU believed was right or not IS NOT the point.
The POINT IS they were willing to risk their lives for you.
Policeman "risk" their lives (supposedly, although I am sure some would never do so, such as many soldiers would not), but there are a lot of policeman that certainly deserve ZERO respect.
Just like the soldier that is in jail right now for raping a 14 year old Iraqi girl and then murdering her entire family. Why should I respect him? Because he "risked" his life?
I have No respect for that human who was a soldier. A job should not be respected universally, the individual should be evaluated instead.