Have you ever taken up arms - and pursued an armed enemy - that wanted you dead?
I would be interested to learn what "set of principals" George Washington considered appropriate for his time and his war. They may or may not be applicable in whole in our time. I doubt if George ever contemplated the weapons, enemy mentality or war conducted against civilian population centers we face in today's world.
Generalizing about the virtues of "honorable" war making - is best left to the Priests and War Crimes Judges. There is nothing "honorable" about war. It demeans and destroys those involved. Only the FR keyboard "warriors" see romance, heroics and swashbuckling honor in war. The real world warrior had best concentrate on accomplishing his mission and staying alive at the same time. One mistake, one hesitation, one reckless act can get you killed in an instant - and you stay dead, forever. Tends to keep you focused and vicious.
We send clear eyed, fresh young men into situations - that change them into hardened and bitter warriors looking for revenge. They find their brothers butchered alive and left for them to find. They find entire villages brutalized by the enemy they have been following/chasing for weeks. Can you not imagine the acts of war that take place - once these two opposing forces finally can not escape one another and must each fight to kill one another?
Men at war become something else. Much can be found to criticize - but your voice on this matter would perhaps sound a little less offensive if you had been there and were not guilty.
Semper Fi