At least during WWII, everyone served in some capacity, odds are if you were over 18, you were fighting somewhere, and of course even on the home front, everyone got involved as well. The country was united.
Every war ever since, has been a case of only a few actually fighting, and back home, it was far from united, as we saw with Vietnam. People back home didn’t relate to the soldiers that were returning, some even despised them, calling them “baby killers.” And of course the saying during the Iraq was “While the military went to war, America went to the mall.”
“Every war ever since, has been a case of only a few actually fighting, and back home, it was far from united, as we saw with Vietnam.”
Since WWII we have also never fought all out to destroy the enemy once and for all, as quickly and efficiently as possible.