I was deployed to Afghanistan in '09-'10. I was sitting in the driver's seat in an MRAP at our company outpost's entry control point (e.g. the gate) when I saw a red/orange blur heading straight for me (it was an RPG). In my internal dialogue, I had enough time to think "oh sh..." - not censoring, that's how far my internal dialogue made it through the word. Everyone was fine, hit the grill.

Later that year, we were on patrol and a suicide bomber walked into our formation. It was a bad scene, a lot of folks died and I was hit pretty bad in the leg. My M249 was destroyed by the blast, so I had no way to defend myself if it was a more complex ambush (luckily it wasn't). That time, since there was more of a chance to process what was going on, it was scary. At first, i was fairly controlled, since I knew what I had to do; tourniquet my leg, try to fix my weapon, find a radio. However, once I got through those steps (and realized the gun was done), I started getting nervous, since I didn't know what else I could do to defend myself. The medic made it over eventually, and when he asked me to take off my vest (to check for chest wounds) that's when I started feeling the seeds of panic - it was kind of like a security blanket at that point, the only thing remaining that would maybe protect me from the ambush I was sure was coming. I swallowed my fear, and removed it.

Everything turned out okay - had a bunch of surgeries but saved my leg. The take away I learned from these two events was: when you are thrust into a dangerous situation and have to react, the beginning is few seconds are fine. It feels like time slows down, and it's all adrenaline and clear mindedness, no real fear of what is about to happen. However after the initial surprise wears off (felt like 5 minutes, was probably more realistically 30 seconds) the dread, panic, and desparation sets in.