Ordinary people fight for a cause. As long as the cause is justified.
Countries go to war to help their economies which is a totally stupid idea.
War is the means to suppress another nation to compliance.
In some cases there may be merit for force and yet in majority of times war is the wrong tool to solve problems between nations.
Being that humanity is adversarial the Army serves a dual purpose, employment as well security.
"War is diplomacy carried on by other means" Clauswitz
Countries do not go to war to fix their economies.....war destroys econmies, it does not fix them. Witness our current mess, partly brought on by massive US deficit, largely because of the wars.....