Chimps go to war and will tear each other to pieces and celebrate it. If they had the capability to make nukes, they absolutely would.

I never got why people just assume that animals are somehow morally better than humans. The only things holding them back from committing war crimes are a prefrontal cortex and opposable thumbs.

The fun parts about animals is that the more intelligent they are the more they kill for fun instead of just survival. Most of the smartest animals are absolute dicks. Primates are absolute psychopaths while the smart sea mammals like dolphins and orcas enjoy torturing other sea animals for fun. Crows can pass down grudges through generations and will participe in wars with other crows over minor issues building up over time. Elephants rape and then kill other animals like Rhinos if they don't get any action from females from their species. Intelligence encourage this kind of seemingly pointless behavior. You don't see other animals behave that way. If they kill something it's either because they think it's a threat or because they need to eat it to live.