Why miht a civilian enlist to serve in war?

A civilian might enlist to serve in a war because they may feel they have an obligation/duty to serve and defend their country. Also, they may have had family in the military and want to keep that family tradition of service + sacrifice.

Comparing Military Pay and Benefits To Civilian Jobs. Military life is like civilian life in many ways: for the most part, you work a regular job, have to keep your life, bills, housing, car and other things in order ... With tax advantages, pay is comparable to civilian sector pay. Usually higher than military pay.