There is an interesting free video on Stratfor.com discussing the issue of technology and war. Basically they argue precision weapons have changed how wars will be fought and the moral calculations made in war.
In 1900 a land fighting unit would have had artillery, rifles and bayonets. They didn't really have the ability to target an individual. The only way they could have gone after al-Awlaki would have been to invade whatever country sheltered him and fight a massive traditional war. That sort of thing started World War I for example.
Now the military can send in drones, collect phone intercepts and target one or two individuals. They can find a guy like al-Awlaki or bin-Ladin and kill him without an invasion.
In one sense that is good, an airstrike in Yemen is preferable to an invasion of Yemen. On the other hand we're acting like judge, jury and executioner when we use a drone because the target can't really surrender. That might not be so uncomfortable if we could limit drones to hot war zones. But the fact that our targets hide where soldiers aren't actively fighting opens a new can of worms.

