Study the ancient world and it quickly becomes evident that pillaging was a common activity. Rather than developing your own economy, your team would sack some other cities and haul the loot home. Conquest and theft were hard to differentiate.
Last night I was reading about the "Hunger Plan" that the Nazis had for Russia and Ukraine. It involved sending food back into the Reich and letting millions of the local residents starve to death.
The ancient evils are never ancient.