We didn't get Bin Laden during the invasion Bush let him go, by the time Bergdahl left it was an illegal occupation.
I never read that story that Bush was there at the Tora Bora, had Bin Laden in grasp and let him go. Has Bush even been to Afghanistan? Ever?
As for it being an illegal occupation, first you said it was an illegal war because no formal declaration of war had been made, then you asked why we're still there, now its an illegal occupation. Sorry if I don't have faith in your understanding of what constitutes an illegal war or illegal occupation given your lack of consistency.
The bottom line is Berghdal is being charged as a deserter even if he is arguing he was just going to the next base. Also, I haven't seen any stories of any other soldiers having issues with that particular base. And lastly, his dad's little prayer in Pashtun during that White House ceremony and their back and forth emails while Berghdal was still on base certainly raise the question about his son's loyalty to the Army as a whole.
I recommend informing yourself of all the facts in this case rather than just the information you WANT to hear...