To Kill and to Die for a (Multicultural) State

When is a state authorized to demand of its civilians to sacrifice their lives in war? When is it authorized to demand of its soldiers to kill soldiers of an opposing army in war?

According to politico-liberal theory, a state is authorized to oblige its civilians to participate only in a defensive war. However, some groups in Israel believe that a state is authorized to demand of its civilians to participate in a war of necessity, such as a war rooted in religious elements.