I think I know what you're trying to say; more often than not two individuals viewing a situation or idea with different persepctives will reach the same conclusion and act on that conclusion with identical motives. For instance with your example of the war in Iraq; Al Qaeda, the insurgents or any resistance to U.S. forces view our reasons for being there as different than we do [perspective], but still reach the [conclusion] that it justifies their acts of violence towards us - because it's beneficial to the well being of their country, or so they think [motive]. As is our conclusion for our acts of violence against them.
It's an interesting speculation to say the least, but I believe it's a highly superficial one, comparitive to looking down at a city from several miles up. If you put just a tad more thought into it you will see that it's just as likely for people or a group of individuals with differentiating perspectives to reach different conclusions, or vise versa. It depends on several variables, and you are not drawing on enough examples to make your speculation even remotely distant to being correct when applied to a wide variety of situations. Though it is specious in some cases.
P.S. - You probably should have put this in D&D mate.