Found it at last.

You'll have to forgive an old bloke banging on about his hobby just once more! Mark - do you remember ages ago I asked if you remembered a card game we played as kids? I'm pretty sure it was actually yours. It was all about spies and stuff and was set in the desert. Well ... I've found out what it was called - Foreign Legion and someone else on BoardGameGeek remembers it as well. Here's the picture, click on the link for more info. Does it ring any bells ... I guess it's too much to expect you to still have it!