The problem with this answer is that it contradicts itself. IF The Good is involved in a war with the Evil you could say it was caused by the Good but that would mean that not opposing evil is not evil BUT THAT IS THE DEFINITION OF EVIL.
Nor can you say that a side that calls itself 'religious' must be believed. is there no false religion?
The Gods of War: Is Religion The Primary Cause Of Violent Conflict?
by Meic Pearse
just one example among many:
historian Meic Pearse debunks the common misconception that religion causes war. He argues that while religion is often a significant generator of armed conflict both in the past and in the present, the two principal causes of human warfare are in fact culture and greed for territory, resources or power. Since culture and greed often clothe themselves in religion, wars fought for culture often appear to be fought for religion.
And modern history is replete with murderous regimes founded on a similitude of RELIGION
This has been studied extensively by Michael Burleigh.
- The Third Reich: A New History (Macmillan, 2000)
- Earthly Powers: Religion and Politics in Europe from the French Revolution to the Great War (HarperCollins, 2005) ISBN 0-00-719572-9
- Sacred Causes: Religion and Politics from the European Dictators to Al Qaeda (HarperCollins, 2006) ISBN 978-0-00-719574-9
- Blood and Rage: A Cultural History of Terrorism (Harper Collins, 2008)
This paper teases out the many false assumptions in the question and answer
“The Abusive Exploitation of the Human Religious Sentiment”: Michael Burleigh as Historian of “Political Religion”.