"I think there are two criteria to consider:

1: Is the cause truly noble? If not, then we might be able to respect those who risk their lives for it, but we do not revere or praise them.

2: Do they fight honorably? If not, then they do not deserve respect (except maybe for the "dangerous animal" kind of respect I mentioned previously). Even if the cause is noble, those who fight for it only deserve respect if they fight honorably."

So an Englishman of the 18th century were to judge an American militiaman as a "dangerous animal" for (a) committing treason to his king to whom he had sworn an oath (b) bushwhacking officers from a forest without standing in straight lines, within gunshot range s in full view of the enemy,- thus fighting "dishonorably" as per the prevailing notions of "honor", he would be right?

Whether a cause is "noble" or not depends on who is doing the judgement. An Islamic fanatic who joins the Taliban can sincerely believe that he is fighting on the side of virtue and killing hellbound infidels who disobey God's word. To you his cause isn't noble. As for deliberately targeting citizens, that is precisely what bombing German cities, or Hanoi was.

Was dropping the Atom bomb or Hiroshima "honorable"?(Not saying Americans are particularly ignoble. Every army in history does what it takes to win and calls it "honorable", while the oppositions effective, uncounterable tactics often get called "dishonorable". )

What "fighting honorably" means, evolves over time and is almost always out of date. Knights called muskets dishonorable because a peasant could kill a knight from afar. Oh the horror. As did the Samurai. Hey Afghan insurgents think drones are dishonorable. American soldiers think IEDs and suicide bombers are dishonorable. Hmm.

English commanders complained that the American soldiers in the American War of Independence didn't fight "honorably" or 'like gentlemen'. Targeting officers was considered dishonorable and criminal. Wellington refused an artillery officer under his command permission to fire his battery at Napoleon because it was 'dishonorable'. Of course, Americans paid no heed because the tactic was effective. Sherman burned Georgia,and after the Civil War used the same tactics against the remnants of the American Indian tribes. These days, incinerating a city full of civilians from the air is "honorable". Poor Sherman was accused of barbarism for burning one city.

Coming to modern times, how is a drone attack blowing up a house full of civilians to target one insurgent commander "honorable"? You can argue it is effective. But honorable? You are fighting people with a technology they can't fight back against.

Should the Afghan insurgents fight F16s and Abrams with AK 47s while wearing distinctive uniforms so they can be picked off? That doesn't make any sense.

As a thought experiment, if you were an Afghan whose family were killed because drone operators half the world away mistook a wedding party for an insurgent group, would you be worried about conforming to the invaders notion of "honor"?

Martin Van Creveld has written a whole book, aptly titled "The Transformation of War" where he gives dozens of examples of practices that switched from "honorable" to dishonorable and vice versa with the passage of time.

(From Wikipedia).

The book's significance is attested to by the fact that until the middle of 2008, it was included on the list of required reading for United States Army officers, and (with Sun Tzu and Clausewitz) the third non-American entry on the list..

Well worth reading. Here is a sample of his writing. "Knowing Why Not To Bomb Iran Is Half the Battle" http://www.forward.com/articles/1254/ I don't always agree with Van Creveld but he makes me think.