This book explains when wars serve national policy. For example, authoritarian states who failed to handle the Pandemic would also strongly suggest a tragedy must unfold to retain power.

"The Dictator's Handbook: Why Bad Behavior is Almost Always Good Politics" ( 2011, Bruce Bueno de Mesquita, Alastair Smith )

https://www.amazon.com/Dictators-Handbook-Behavior-Almost-Po...

Not a pleasant read, but a well reasoned model of violent human behavior. =)