Another angle, inexpensive, increases odds greatly, can be learnt from home(initially)
Langauges...
Options-
Dari/Farsi(or persian as both are generally known) for Afghanistan.
Arabic(usually Egyptian or Saudi dialect is best) for the middle east, north Africa.
French for a lot of Africa too.
A westerner with conversational second langauge skills is almost as employable as a paramedic to a security/liason contractor. It is a real big deal to certain employers. With a shift from multinational to local contracts a guy who can at least bumble through conversation with the locals opens a lot of doors. Don't get me wrong, learning a new language is a big undertaking. But two main facts are its inexpensive -using tapes, occasional night school class, finding native speakers in your community own suburb who might help etc. And there are no tests or failures, you get as good as you want.
I say to a lot of my civvy buddies who want to come over but left it too late to join the army. If its really that important to you, become James Bond so to speak.
A civvy with langauges and medical skills makes you the sh*t in a warzone. Also don't forget volunteer work if you can get away for it. As long as whatever group it is feeds and shelters you its a great free ride for experience and a foot in the door to meet paid contractors. Especially in Africa. Email St Johns ambulance in a dozen African cities. You will have half a dozen replies in a week saying they'd love to have you help out.
And don't let age stop you. All the 50 and 60 year old walking coronaries I see contracting over here means anyone can apply lol.