A child at cheder has asked my mother as their teacher: ’how could the Jewish people kill everyone in Yericho when they/some of them had not done anything wrong (sefer Yehoshua)? Many thanks.
In a primitive world 3,300 years ago, which was run by force, and any “new nation on the block” was greeted with violence and pillaging, we had no choice but to defend ourselves and to deter anyone from “starting up with us”. Yehoshua would have been much happier to acquire the Promised Land through buying “dunam after dunam”, but unfortunately, the primitive world saw it as “all or nothing!”. This isn’t a coincidence, for just as by young gangs, the one with the largest muscles rules and sets the rules, so too when mankind was immature, power decided one’s destiny. Israel doesn’t live in a vacuum, and an eternal nation who wants to survive and be relevant, has no choice but to relate to the world in its own form, and in the “language” of every subjective generation. Paganism was inevitably connected with immorality. It’s not a coincidence that the epitome of idolatrous religiosity was human sacrifice! Because as soon as you have 2 gods, inevitably they’ll be fighting with each other, because each wants to be “king of the hill”. The problem with that, is that all religions emulate their gods (“imitateo dei”), so their followers will also justify their constant fighting. In addition, as soon as you have 2 gods, that infers that each of them is lacking something. That’s why mythology is comprised of the gods taking and fighting for that which they lack. In short, their gods are “Takers”, and that’s who pagans emulate and “idolize”. In contrast by monotheism, we believe in 1 God who, by definition, is perfect, and lacks nothing. Our “imitateo dei” is to emulate a God who is a “Giver”, not a “Taker”. Giving is at the top of our monotheistic agenda, and isn’t at all on the pagan program. In other words, the idolatrous world isn’t “innocent”. Polytheism isn’t just a “mathematical” problem (are there 2 or 20 gods instead of 1), but it’s a moral (!) problem. When Avraham was told to go to Israel and build a moral and just model nation to influence the rest of the world (e.g. Breishit 18, 19), and bring blessing to all mankind (ibid 12, 3), it was totally antithetical (opposite) to the violence of the accepted pagan practice, where it was accepted to murder one's wife, children and slave (and how much more so, to kill us foreigners!). This all changed with Akeidat Yitzchak where God dramatically commanded: "Don't lay a finger on your son. No more human sacrifices!". We couldn’t influence anyone in an atmosphere or culture where violence rules, and wants to force us to be their slaves. In short, it’s very common for children to ask questions which are good, but anachronistic (out of the actual historical context).