I would say a good quality First Aid Kit, preferably with Sterile Syringes (I'm assuming you're hauling hold luggage) is a must and if you are carrying hold luggage you can (probably) get away with packing a multi-tool type item. What I would definitely add, and you can carry this on your person as there mostly plastic and as light as anything, is a Combat Application Tourniquet (Amazon do them for around £20). Life saver in a drama big time (and you can apply them on yourself if you're not flapping too much!) Oh, and a torch, all the preceeding is irrelevant if you can't see you hand in front of your face!!
Get a good Bum-Bag to stash your EDC in, and if you're in a country that's got handy pick pockets thread some wire through the belt to stop them subtly cutting the belt with scissors on a crowded street/train/bus and heading of with your passport/Docs, FAK and beer tokens.The main thing is preparation. I'm assuming you'll get at least 24 hrs notice of your destination so check out the area, get mapping and/or familiarize yourself with the place your going. The images on Google maps may be about a year and a half out of date from when they were taken but can still give you the lie of the land and show Hospitals, Embassies and Airports etc.
The comment about dollars is absolutely sound; I've got myself through a roadblock that way as well as bartering with cigarettes (be careful though). All this is irrelevant if you're in Stuttgart or Washington for a conference, but if you find yourself further afield...
On a handy note, buy a photographer's waistcoat type thing, the sort with all the pockets. They fit under a jacket easy and you can fill them up with stuff and still have a load of room in your carry-on or you can forgo the hand luggage all together, as some airlines are pretty s****y about size/ weight etc and charge. Most models have a large zip pouch on the lower back that can accommodate a small laptop or tablet.
Hope this helps
