Do you believe it's plausible to change your views? I think the most likely situation is that he thought he knew what he was getting into, and, through his access to lots of top secret documents, ended up learning more things, and thus changed his mind.
I mean seriously, have you never gotten into a situation where you learned information that changed your mind?
He's not perfect, obviously. Joining the army when he did was stupid as hell just for staters, I don't think we disagree there. Does that lapse in judgement signal a broader permanent disability of some sort that will follow him for the rest of his life? People change, you should know that.
If he says that he decided that the war was objectionable after he joined, I believe him. I have no reason not to, nothing about somebody changing their mind conflicts with my mental model of normal people with agency of their own. Normal people with their own agency can change their mind, that isn't suspicious.
As I keep pointing out (and nobody has refuted), nothing in the State Department cables revealed any unconstiutional or even awful activity. So our diplomats also spy on on other diplomats they meet - shocker! This is what diplomats do, and intelligence-gathering is a normal function of embassies. The trouble with Manning's argument from principle that it doesn't really explain the bulk of the leaks (I have acknowledged repeatedly that leaking materials which appear to show actual war crimes is justifiable).
* I'm using the male pronoun because that's the identity he was using at the time. As of today she is now living as a woman and has changed her name to Chelsea Manning. http://en.wikipedia.org/wiki/Bradley_manning#Gender_reassign...
My thesis is not tha the joined with the intention of leaking secrets. My thesis is that he joined up thinking it would help him straighten out his sexual identity issues and when it ended up making them worse it's unfortunate (largely for himself) that he didn't seek a medical discharge on basis of his gender dysphoria and the severe stress it was causing him. I don't think he's an inherently bad person, but if you're going to carry a top secret clearance you have to be aware that that's some Serious Business.
Do you have any experience with people?
More than you seem to imagine. It's because I've spent so much time out at the fringes of society that I have so little patience with this infantilist bullshit. Like Manning, I left home and (broken) family at a young age to make my own way int he world, instead of going along with the crowd on the conveyor belt. I sympathize with him, but I also think that respecting his right to make his own choices also involves investing him with the responsibility for the outcomes of those choices.
I like what I see of Manning, but think he made some catastrophic mistakes that's he's going to be paying for for the next few years. Your view of events is predicated on him being a helpless automaton that joined the army and earned a top secret clearance without understanding what any of that meant, which is to deny him agency for his own actions.