Back, about 18 months ago, I suggested that a good military needed six attributes. I still hold to those views, even more with the basics as I worry, more and more, about problems in, especially organization and in leadership and management.
I am not a great fan of the late Field Marshal Montgomery; he was, in my opinion, a good general but not, quite, a great one (the Brits had some great commanders ~ Wavell and Slim to name just two in the Army). But he had some solid insights, and this is one of them:
Discipline is, in my opinion, the sine qua non, of the good soldier; discipline is what helps him (or her) to overcome his/her natural, normal, human fear. It helps if (s)he is tough, well trained, adequately equipped, properly oragnized and well led but all of those things take second or third place to discipline.
My thanks, yet again, to my friend The Regimental Rogue.