In Thucydides Melian dialogue he famously wrote about the Athenians. At the time, Athens was at the height of its glory. It’s intellectual achievements would not be surpassed by any state for nearly two thousand years. Ancient Athenians prized democracy and ethics for themselves. They knew they were more advanced than the rest of the world and got cocky. They start conquering other Greek city states. One of them was Melos.
The Athenians demanding unconditional surrender or they would destroy Melos. The Melians pointed out it had not threatened Athens and how unfair it was. According to Thucycides the Athenians replied… “you know as well as we do the right, as the world goes, is only in question between equal power, while the strong do what they can and the weak suffer what they must.”
Its a phrase nearly every general in America knows. In that one phrase Athenians abdicated their belief in ethics. They conquered the Melians but it was only a matter of time before there was blowback for their unethical behavior. Sparta defeated Athens. Then Macedonia defeated both weakened Sparta and Athens. And then Rome defeated the Hellenistic empire. And that was the end of ancient Greece.
Having no ethics can work on an individual level. Some criminals can get away with it too. Sometimes even a nation can get away with it too. German Nazis though they were doing great.. until their country was levelled. On a civilization level though, from a statistical standpoint, there is always blowback. There is no way to escape the physics of morality on a civilization level. It’s like arguing one can ignore gravity walking off a cliff.