They just enjoy murdering people.

The purpose of terrorism is to spread fear in the population beyond the immediate victims and their families. This is done to achieve political gains by intimidation that align with the terrorist actors agenda in the region. Terrorist organizations, like the US military and intelligence agencies, figuratively and literally use the blood of their victims to write a clear message visible to all the world: "submit!". Critically, they want their victims to give up all hope and cower in fear instead of resisting.

Trying to get as many war crimes committed as possible ahead of the midterms?

Cruelty is the only consistent thing about the Epstein Empire

"Cuba's next."

they're bullies, so they target the smaller and the weaker

And Russia, obviously.