You need to narrow any idea down so that it is entirely answerable within your word limit. I think one clue is in your mention of 'primary sources'. Could you for instance look at the way WW1 casualty figures were reported in elite newspapers? The terminology used in obituaries/death notices reporting the deaths of Britain's aristocracy? Who did this impact on support for the war at home? These newspapers (and heaps of regional papers which would make an interesting contrast) are all online at http://www.britishnewspaperarchive.co.uk/ (with a good search facility). You could make brief references to the impact that this had on the future of the aristocracy in Britain (ie. the death of eldest sons who then didnt inherit etc) without getting yourself into questions/arguments that you havnt got space to answer. You have already spotted the problem with taking Germany as a subject - you don't read German - so I think you can forget that one, however interesting it sounds, yo have to be practical!