Let's just start by saying that I enjoyed this film and it's certainly a lot of fun, with some great comedic performances and a generally stellar cast. Direction, sound and scripting were all sufficient, though none really stood out, and the core message was both worthwhile and refreshing, especially for the war-film genre.
It is a shame, then, that having watched the film and had my interest piqued, it turns out that the plot is heavily fictionalised. Some deviations are understandable, such as the use of the Nero Decree as a key plot point and reducing the scope of the mission to a smaller, more focused group of individuals (underdogs are always easier to root for). Others, however, seem a little odd. Why set the American government as a partial villain, with the Roosevelt administration consistently questioning if the program was even worthwhile throughout the film? The reality is that the government backed a much larger and better-funded equivalent than is portrayed and it doesn't really add anything to the plot. Similarly, why include the death of Jean Claude (over a horse, of all things)? There is apparently no basis for this in fact and it doesn't serve much purpose in the film, either, given that the earlier death of Jeffries has already provided the "unifying" team moment and central tragedy.
Still, I am glad that someone has managed to make a big, Hollywood war film that focuses on this particular message. War is a terrible thing and the loss of life is appalling, but the destruction of a cultures' history is arguably as heinous a crime (if not more so), yet we rarely think about it or account for it. The destruction of Palmyra has hopefully highlighted these issues to a wider audience, but cultural loss remains a depressingly common aim of war. Personally, I would argue that the direct targeting of cultural heritage should be a war crime and heavily vilified, yet the reality is closer to the opposite. I doubt the Monuments Men will manage to alter these long-standing tactics, but if it introduces even a few doubts across the Western world it could be very worthwhile, in the long run.