around is the people who shot this down thought they were shooting down a ukrainian military plane. how difficult is it to hit the thing you intend to hit? >> ideally, the way this would work if it was under regular military control was the sa-11 system usually has three to four vehicles. one of them is a command vehicle with an acquisition radar which sorts through everything in the sky, decides what a target is, and then passes it to the target engagement radar associated with the missiles. what i suspect happened -- and this is just my opinion, but i suspect what happened is these guys got ahold of just the transporter erector launcher vehicle with the missiles on it. it also has a radar. it's a target engagement radar, but it's a lot less discriminating than the acquisition radar. if they locked on to this thing by mistake thing it was an am-26 or cargo airplane and shot off a missile and got malaysian flight 17 instead. that's what i think happened. >> dan, of course you're one of the greatest soldiers that