in vietnam, it could take weeks, but now wounded can be home in days. cnn was granted exclusive access to see the medical care that makes it possible into injured troops. some, hours off the frontline. in the hospital hallway, army specialist james dennis is being shipped home after being in three attacks in three weeks. he had already been here before. he survived two roadside bomb attacks in the same day, and then a coup of days ago -- >> indirect fire. i was hit by a mortar. >> reporter: but still smiling. >> i'm good right now. they gave me some medicine. >> dennis ordered junior troops under fire to run for safety. he couldn't get away in time. >> i didn't even get to start running. and i guess it knocked me out because i remember pushing myself up off the ground and had blood all over me.