Sounds like you've got a good psycho terrorist now, and I hope you open up to him and trust him. Sounds like he's starting out right.
In my spare time, I've put together the following. It consists of your timeline as I have gathered it from the posts here, so it may be off. But I think it is substantially correct. I have also added in my comments on military procedure, and some comments on where I think your false guilt has come from.
Let's start with a review:
You are at a camp with some equipment, and you and the equipment need to be transported to another base, where you can install the equipment. This equipment is what the military calls C-cubed (Command, Control and Communications. In an irregular war like Afganistan, C-cubed is vital equipment. Even the internet entertainment value is very important. So, at this time, you are nothing more than a military machine with some other machinery that is at point A and needs to be moved to point B. (I am not being sarcastic when I call you a military machine. I want you to see this from a completely objective point of view. So hang with me.)
Your initial transportation, a chopper, has broken down. There are now five options: 1) a substitute chopper to point B; 2) a convoy to point B; 3) stay until the original chopper is fixed; 4) a substitute chopper back to main base; and, 5) a convoy back to main base. Options 1 and 4 are ruled out because of the time of day - not enough time before dark. This probably rules out 5 because of distance.
So the discussion comes down to options 2 and 3. For whatever reason, option 3 is not attractive to the base commander and maybe his people, so option 2, the convoy to point B is looked into.
So the convoy questions come up. Is there time? Is there available equipment? Are there available personnel? Can the military machine be moved this way? The answer to all four is yes.
So the machine (you) are asked, do you want to try? Your answer is the one that is trained into you - which is get the job done, right, and ASAP. You bring up the point that your unit SOP is only movement by chopper.
At this point, standard army regs say the commander on the ground has priority command. In other words, if the major in command of the camp wants the convoy done, it's going. Period. Your yes or no has little real impact on the convoy movement. Even your colonel cannot countermand such an order.
But you want to get out, and you want to get your job done, so you offer to call your colonel. Again, your offer to call simply raises a little of the pressure off the major in command of the camp. If your colonel says ok, then it is a go. If your colonel says no, it can still be a go, as the major still has the final decision. (And keep in mind that the major is probably being prodded by some higher up to get that equipment to point B.)
Again, I am not being sarcastic here, but you as a sergeant didn't command a major and a colonel to put together and run a convoy. Your yes and call only cleared some stress from the major, they didn't make him form and send out the convoy. So there is no way you can blame yourself for the convoy being formed and run. You were a military machine that the major decided to move from point A to point B. The fact that your training, your personal job, and the lousy area all made you want to go had little to no impact on the major's decision. Keep in mind that there was a broken chopper at point B, and a perfectly good mechanic at point A. While the initial discussion focused on getting you to point A, it could have as easily focused on that other military machine - regardless of the fact that different units owned the chopper and the mechanic.
So any guilt on the formation of the convoy is false guilt, having no basis in reality or logic. The basic fact is that the major decided on the convoy, and your willingness to go along probably had less impact on that decision than the availability of the MRAP. Again, these are the bare facts, and I am not being sarcastic. Let's even throw in a what if. You called, got a captain who said no, and you went over his head to the colonel. There is no difference. The colonel made the decision that the C-cubed equipment could go by convoy. Doesn't matter if you brought it up, or the sergeant major told him what the stupid captain said. The colonel gave the go. You did your job, notified your chain of command of the situation, the commander made his decision to go.
Another what if. You said chopper only, the camp commander called your colonel, and the colonel said go. Would you have gone? (Hint: They don't let you have those vests when you're in front of a firing squad.) IN ALL THE ABOVE CASES, THE COLONEL AND THE CAMP COMMANDER SAID GO, and you went.
Earlier, I said, and I think you took it for sarcasm, that your could lay the blame on George Bush more easily than it could be laid on you. That wasn't sarcasm, it was cold hard fact. You were a soldier, you did your job in informing your chain of command. That chain of command leads to the oval office, and he was about as far above the decision level (colonel) as you were below it.
So despite your feeling of guilt that this convoy was formed to get you to point B, you had little to no relevant input in the formation and running of the convoy. Again, this is a military fact. I'm not trying to sugar coat anything, I'm not using sarcasm. Again, feeling guilty is NOT an indication of real guilt.
As for Greg going along, he volunteered to join a convoy that might enable him to get back to main base sooner. The fact that the convoy was formed to move you is irrelevant. It could have as easily been formed around him, and you might have volunteered.
And again, the camp commander trumps everything. If Greg had decided to stay behind, he could have been ordered along. Logically, with the convoy going to where a broken chopper was, taking a stranded mechanic is a no brainer. If he can't fix the thing, he can tell the base what parts to send, and save a double trip.
So again, there can be no logical blame on you for Greg being in the MRAP.
Next, for you, come two bangs. One that stops the MRAP, and one that hits your chest.
You wake up later with a lot of pain, and under the influence of all the pain meds. While you say you felt guilty at this point, I would think that any guilt you felt only came because you were told that others died. And some guilt is normal in that situation. Mostly you were dealing with pain and meds.
Also, I think that how you were told that Greg died has had a lot to do with your guilt feelings. And even at that time, you were still under medications, which would affect your ability to handle that emotional stress. The later anti-depressant problem has just multiplied it. Being told that someone died to save you is bound to bring on guilty feelings.
But guilty feelings don't make you guilty. Let me repeat that. Guilty feelings don't make you guilty. Human beings are incredibly able to manufacture guilt out of nothing. That is the most important thing that you need to understand.
Add to all of this is your normal tendency to feel guilty and to blame yourself if things don't go right - no matter whose fault it really is. Thus you get a severe case of false guilt.
No one knows what brought Greg out. We've talked that over before. But that was his choice. He was trying to do good. The ones to blame are the haji. At that time and place, they had the freedom of choice, and everyone else had to react to them and their actions.
So look at it all logically, and take the blame off your shoulders. It doesn't belong there, and it is hurting the healing of your chest and emotions. Yes, the guilty feeling is real, but the way to remove it is to acknowledge that there is no real basis for the guilt. The sorrow and pain are enough to work on. Don't let this false guilt of blaming yourself for Greg's death impair your ability to heal.
Let me leave a final thought. If you had known Greg before, and this exact same scenario had happened, but with someone else in your unit instead of you, would you blame that person for Greg's death? And if not, why are you blaming you?
Hopefully,some food for thought and healing.
Love, prayers, lots of gentle
and holding you in my arms as you sleep.