I'm working for the International Red Cross Red Crescent, so I'm partial. However, the problem you are describing is exactly why I love working for the Red Cross Red Crescent! The strength of the organization is *not* having to send expatriates to a country and a culture that they don't know. Instead, we have National Societies in 186 countries. And the volunteers in these National Societies are locals. They know their culture better than anyone else and are able to find solutions that are appropriate in their context better than anyone else. Of course that doesn't always work without problems either. And of course there are cases where we still send expatriate staff - either because there is a problem that is too large for the National Society to handle and/or to build the National Society's capacities. But I really believe in the concept. It also makes sense financially. For the money it costs to send me halfway around the world you can buy a lot of water pumps, chlorine tablets ...
I always found the "Danger. Mines." t-shirts, that are probably the bestselling souvenir in Cambodia, slightly distasteful - for pretty much the same reasons. If they would say "Stop landmines" or "I support the elimination of landmines" then I'd be all for it. But making landmines a cool fashion-item leaves a sour taste in my mouth.
I'd like to add to that:
"Emergency Sex and other desperate measures" by Kenneth Cain, Heidi Postlewait, and Andrew Thomson. The book follows three young UN workers to Cambodia, Somalia, Haiti, Bosnia, Rwanda and Liberia.