I'v been thinking about the self-priming nature of military involvment.
The simplest expression of it is "they shall not have died in vain" but the process is actually more complex than that.
The longer version is that because the act of becoming a soldier and engaging in warfare involves trading in the moral codes that guide people within their civilizations for a different set that allows for random killing and dehumanizing certain groups, a protective shell is set up to prevent the remorse that such behavior would normally elicit. The protective shell, of course includes all the pomp and circumstance that we use to honor the fallen and the increased stature (and trust) that we place in veterans but the same shell creates taboos that prevent us from discussing warfare rationally. It simply can't be done without someone invoking the spectre of "dishonering the troops"
The tragic result is of course that the possibility of reconsidering bad moves or disengaging from a conflict that has not been emphatically "won" becomes exceedingly difficult.
And as seen from the outside, the behavior that results seems quite insane