Sentence:  This was well brought out in the skillfully conducted campaigns by the various governments in appealing to the masses with their characteristic suggestible subconsciousness, stirring to the very depths the reflex consciousness of gregarious man by all sorts of direct and indirect suggestions of fear of attacks and patriotic reactions of self-defence against such attacks until the evil genie of self-preservation and fear became loose, resulting in a sweeping <WSD>conflagration</WSD> of a war of nations with all the horror of diseases, mutilation, and extermination of millions of human lives, over seventeen and a half millions, according to latest accounts, having perished in this world-massacre of the human race. 
Meaning of the word marked with <WSD> tags:  A large-scale conflict.