Modern Ambushes

I don't think that the section about ambushes in war could have been presented to us at a better time. All I could think about the whole time I was reading it was the American Sniper controversy and all of the arguments for and against the actions of [great] men like Cris Kyle. I have never once questioned the necessity or morality of snipers or other soldiers that achieve their objectives through subverted means, but many people (especially recently) have been doing just that.
It has been said that snipers are "cowardly" for not fighting openly.... I'm not going to dwell here long for fear of getting thrown off of the blog due to my explosive anger, but I would just like to say that, like Aquinas, I believe that ambush warfare is completely valid and in no way is unjust if done in the pursuit of some righteous cause. And is, in no way, cowardly.

P.s. I commented on Abbey's post