This is nothing new, history repeats. Prior to the invasions of Afghanistan & Iraq there were numerous regional experts warning that the result would be chaos, failed states, a rise in extremism and long term instability in the region and indirectly the rest of the world. Millions of us marched through the streets, asking our governments not to make what was obviously a massive mistake.
The US & UK governments were convinced that they would recreate the liberation of Europe, with cheering crowds, flowers in their hair, Mission Accomplished banners and then simply totally dismantle a government & civil service and recreate a new one to their favour. Groupthink is a powerful thing.
At one point you have to consider the possibility that destabilisation is the objective and the apparent stupidity just an excuse.
In the case of Israel, destabilisation and creation of a region of neighbouring failed states is absolutely it's aim as that is an exploitable situation. Iran was the only real opposition to Israel's long term colonial expansion and ethnic cleansing and more recent outright genocide. It was also opposed to Israel's existence and funded terrorism, etc... (whatever caveat the reader needs to understand I'm not a cheerleader of Iran) but historically it is not alone in this and is not the only country ever to be hostile to another. The majority of such situations resolve over time through diplomacy and reason, and yes, significant amounts of violence but it is rare to resolve such an international dispute purely through war. Israel, its government and military have long been clear that they don't seek a status quo, but a chaotic forever war they use to justify their literal bulldozing of surrounding nations.