x2 on the Spyderco Millie.
I just returned a few months ago from Afghan, I patrolled everyday in one of the worst areas in the country. I carried a Spyderco Military clipped in my pocket and an Esee 4 on my gear. I reccomend something similiar for your friend. If he was ever to be in a situation where he needed to use a knife against an enemy combatant, he would be pretty much screwed anyways. Meaning he would most likely be out of ammo, alone, and surrounded, the latter two will almost never happen.
I would get him a strong fixed blade that is designed more towards utility rather than a knife designed for just combat. I used my esee 4 for everything from cutting c-4 to digging in the ground for IEDs, and after hitting the tip on rocks and just plain mistreating it, the point nor the edge has never chipped. It is one tough knife. I used the crap out of my millie on a daily basis and I still carry it, it is my favorite edc knife. I also brought with me an Esee 5, Esee Izula, Spyderco Tenacious, and a Emerson commander.
I usually carried my Izula in my backpocket, I used it for chores when I didnt want to abuse my Millie. The tenacious was my loaner knife and I eventually gave to a good friend after he pretty much refused to give it back. The Esse 5 is one beast of a knife, I took it with me on a few ops attached to my pack. But it didnt really see much action, it was just too heavy for me but still a sweet blade. I just couldnt keep the Emerson Commander in my pocket, my Millie wouldnt let it, but I still love the Commander.
I hope this helps. Good luck on your seach, and good luck to your friend.
Kenny.