Estimates of how many people were killed during WW 2 range from 70-85 million [!!!!].
The total number of military and civilian casualties in World War I was about 40 million: estimates range from around 15 to 22 million deaths and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.
What is the root cause of every single one of these deaths?
Bad middos. That simple. The bad middos of bad people who started [and the bad guys who fought in] these wars.
About 50 thousand dead [estimated - I don't count] and countless more injured and suffering greatly on the Arab side of this recent conflict. Not to mention all of our casualties.
Why? The bad middos of bad people [I refer of course to Hamas].
From the beginning of time, almost *all* [not only wars] of mankind's problems have been caused by bad middos. דוק ותשכח.
The only way to fix your middos is learning mussar *properly* and/or going for therapy. Not doing so is at your peril. Often the greatest victim of מדות רעות are not the people who surround the person with these middos but the person himself.
An absolute פלא [!!!] how few people are on a daily journey of refining their character.
הַחֲזֵק בַּמּוּסָר אַל תֶּרֶף נִצְּרֶהָ כִּי הִיא חַיֶּיךָ. [משלי ד-יג]