If anyone can clarify the events and socioeconomic reasons behind the war that would be great.

So the term war never changes says the reasons and effects of war don't usually change but the events leading to and technologies used for war do change.

@Jorilo I would recommend reading the wiki article regarding the entire crisis if you would like to learn the reasons and events leading to the Great War. Think its called Great War, just search it up and the wiki page should be the first result. 

"War Never Changes" can be taken in a multitude of different ways but personally I always see it was having to do with the reasons and rewards of war as tech, equipment, and other things always change but the idea of wealth of money and resources, peace, and ruler ship of it all always come with victory in war. Of course you could look at this from a number of different ways like war is human nature but with a lot of people their theories always center around: reasons (want of Money, Power), rewards (Having Money and Power) and the effects (How they use the money and power), Basically reason leads to rewards and rewards leads to effects. Basically war never changes because the reasons behind war never change.