Yadirf: You said, "Satan caused WWI." How is that? It is unprovable, mere speculation that Satan did any such thing.
If so, who fought Satan in WWI? Was it Jehovah using the rest of mankind to fight the forces of evil? Then, this makes the Bible Student's refusal to fight Satan even more damning.
But, which side was Satan on, the German Imperial Government or the Western allies? Was he on neither side, just stiring up trouble?
The point is that no human can really know. To make allegations about some mythical spirit being called Satan the Devil, and place one's faith in such is blind credulity. The same people that invented Satan also invented a literal hellfire. All these concepts speak more to the tribal nature of human evolution through the ages of superstition and efforts to explain what could not be explained by science ... until later ages.
If Satan literally exist, and he might, then certainly the invention of religious organizations in opposition to the simple individual, mono-e-mono rel;ationship each have with God is the far worse of any sins he commits, far more sinister and effective than even starting a war.
Following Bible principles, we will avoid trying to live - or demand others to live - by an extensive and rigid set of dos and don'ts that go beyond the teachings of the Bible. The Watchtower, 4-15-02, pg 22, pp 15