Having come and gone in and out of Baghdad/USA, this is what I can tell you:
I had several knives, nails, med supplies, packaged food, and various other survival goodies packed loose in my checked baggage. If you get luggage that has a TSA approved locking mechanism, only TSA agents will get into your baggage, which means the baggage handlers cannot open it without breaking it, which does not happen. Except for some non-prescription drugs and alchoholic beverages and explosives (and now lighters) and pressurized flammables, you can check just about anything you would need for a survival kit in checked baggage. What you can't check (a lighter, some emergency fuel etc), you can pick up easily enough at your destination (I snagged a disposable lighter and some cotton balls and a tube of vaseline at the duty free before I even left the airport).
Surprisingly, I was able to bring an awful lot of stuff right on the plane with me as carry on, like flashlights, meds, matches, plastic bags, string, duct tape, gorilla glue, toothpicks, you get the idea. All packed away in my little messenger bag, which they did not count as a carry on by the way, which meant I could hold onto my laptop and my day pack that contained an extra set of clothes and other supplies/gear. I was surprised to find out that there are things I can carry on that can't be in my checked baggage.
If you really want to know what you can and can't do, go to the TSA website and find out. Here's the address:
http://tsa.gov/public/display?theme=175If you really need something you can't take and will likely not find at your destination, then improvise. Ultimately, you can never have enough survival stuff, or you can always make do with what is at hand. Chance favors the prepared mind.