But I don't think your arguement is simpler.
Okay, we don't have evidence that there is (or at least was) an exit strategy. Let's draw a couple of conclusions.
1. There isn't (or at least wasn't) an exit strategy.
2. There is an exit strategy in place that no one outside of X amount of people that know about it.
The first case can't be proven, the whole proving and negative thing. But it is a logical assumption as there is no evidence for an exit strategy. The second case can be proven, and needs to be in order to be accepted, because it is a positive.
No evidence for my space lizards.
1. There aren't any damn space lizards.
2. There are space lizards but no one outside of X amount of people know about.
Neat thing about conspiracy theories, any evidence against is transformed into evidence for it. Of course, I'm now arguing against the existance of space lizards...they got to me!
Saw a great movie today, about Edward R Murrow going up against Senator McCarthy.
McCarthy: Commies have infultrated teh everything.
Murrow: You're an ****** McCarthy.
McCarthy: See! He must be a commie and that proves that commies are everywhere.