How does technology or lack therof explain 2000 crucifixions?

I don't think anyone is claiming a genetic evolution. It has been a memetic evolution.

By "explain" I hope no one hears "justify" (although someone will do it anyway):

You see this with the Romans, too: they tell a city to surrender, it doesn't, the Romans conquer it and practice unspeakable brutality on whomever's left.

So what's happening? They have very limited resources, you forced us to expend them, maybe lose some of our own soldiers, and waste a valuable campaigning season - ok, now you pay the price, and let this be a warning to the next city: if we tell you to surrender, you'd better surrender.

What if the city does surrender? Are those people killed or sold into slavery anyway? I don't think historians bother recording those episodes.

"What if the city does surrender? Are those people killed or sold into slavery anyway?"

Typically, no. The attacker may leave the city entirely intact, or may place their own proxy government. They may take the elites of the city as prisoners, either as punishment or as insurance.

It's not quite so simple, since we are looking at single examples. Alexander was predated by leaders (Cyrus the Great) who ruled in a much more progressive gentle way. Recent history has shown major powers performing very cruelly (genocides under colonialism) and there's definitely at least minor world leaders who would want to be just as cruel. So the question becomes more of why was it effective and strategic to be cruel at that scale in the past but not in the present world, and I would attribute that to technology: better communication, travel, and interconnectedness of trade.

Cyrus the Great gets a lot of great press. Partly because he replaced really unpopular empires. And party because those that he really didn't like didn't give us many sources.

Its very questionable if he was all that nice to the Medians and Assyrian cities.

I would attribute it to democracy. It's very hard to sell war to an electorate unless you can persuade them you're the 'good guys'. Which is harder to sell when you're openly butchering thousands of people.

Many ancient societies had a very different conception of 'good guys' than the modern one. It was very easy to justify very aggressive war with some of these alternative conceptions.

'Good guys are the ones who worship the right god(s) and therefore we get to kill the bad people next door', or 'Good guys are guys who serve the King/Emperor and anything that advances his glory is good', 'Good guys are cultured people and everyone else is a barbarian' etc.

Democracy didn’t stop the Athenians from exterminating the Melians, every adult male being killed and the rest of the population sold into slavery, all because (according to Thucydides), “the strong do what they can and the weak suffer what they must.”

Athenians weren't really democratic by modern standards. Only about 10% the population could vote[1].

[1] https://en.wikipedia.org/wiki/Athenian_democracy

But why and how is democracy a thing?

Eh, I bet it’s more the wide spread, high fidelity mass communication.

You’d previously get word of mouth of what was happening (with lots of us vs them, dehumanizing, etc.). Now you’d get to see it ‘in person’ in 4K @ 60fps on YouTube.

It’s easier to say (and think) ‘yeah, those bastards deserved it’ when you aren’t seeing a very human person have it done to them up close.

Which is a good thing.

I don't think it's that. The main reason behind the brutality was precisely so that people elsewhere would find out about it, to set an example for other cities that they should surrender instead of forcing a protracted siege.

I think it comes down to economics.

Ancient cities were primarily administrative and trading centers for the surrounding territory. Most of the wealth was coming from outside of the cities, it was just collected in the cities. You could kill off most of the people in the city and still keep most of the value because you still have the infrastructure that lets you control the surrounding territory.

By the time you get to the modern era, cities are producing a lot of value of their own. If you kill off the people, you've gotten rid of the whole reason why you want to capture the city.

>Pretty much every culture around the world in ancient times had some sort of moral explanation for why infanticide was allowed.

>https://en.wikipedia.org/wiki/Infanticide

At least half of the history in the wiki describes major civilizations and religions which absolutely banned the practice. Ancient Egypt, all Abrahamic religions, ancient China... Apparently many people did thought infanticide was immoral and did ban it.