To achieve specific goals rather than the total defeat of the enemy
When monotheism first became an idea it was really different and in some cases shocking to what they people at the time believed, they believed in many gods for different things, so the fact that some people believed in only one God was surprising but also in a way seemed like a good deal to some as they only had to focus on 1 supreme being. As we also know, religions with only one God seem to still be around and be stronger than those with many. (sometimes, not always.)
Answer:
The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary. ... Thus began the expansion of the war to include all those involved in the mutual defense alliances.