Let's say they invade Iran ok. That decision will be the result of a well thought out policy decision, perhaps precipitated by real world events in Iran or the region, perhaps by events that are totally fabricated. Whatever, the decision is made. To support some opposition movement or another, or to replace the regime with another, or to create a safe haven here or a no fly zone there, but the logic of what happens once that decision is made is not entirely predictable.
Perhaps the opposition they have courted have their own agenda? Perhaps the resistance they meet is greater than expected. Perhaps an event, say, an atrocity, the bombing of a girls school, creates outrage in the country and across the globe and leads to attacks on US forces across the region. Perhaps a massive successful attack kills a significant number of troops as in Beirut and creates an anti war movement at home.
Perhaps perhaps perhaps. The point is, the INITIAL decision may very well be the result of a well thought out, extremely ideological policy decision (as was the attack on Iraq) but once made, the events follow a logic of their own and those events are often not predicted because the ideological lens of those who make those decisions makes it impossible for them to see such consequences. They can't. They are incapable of understanding the societies they are attacking
