How many people aren’t murdered because of armies though? Humans have been grouping and fighting each other for thousands of years now. You’re under the impression everyone should just… what… pretend it doesn’t happen?
When attacking a neighbor state costs more (because your neighbors have arms too), it’s less likely to happen.
The cold war had plenty of awful hot action with proxies and third parties but the entirely hot version obviously would have been far more calamitous.
I suggest reading Herodotus’ Histories, or you can read up on Genghis Khan, Napoleon, Hitler, Alexander, the Crusades, or the myriad other conquerors and conflicts that have occurred.
