More films about the second world than the first?

Right. The first war was, among other things, the swan song of the old Europe. The topic is way too big for me to want to go into a great detail about at this late hour but in many respects it represented, indeed symbolized, a kind of evolution of the modern world that one can actually discuss,--and many do--without having to go into the issue of battles, which side did what to the other in a particular military engagement. The second war was, as you stated, just about black and white as to the eternal question "which side are you on?". The Axis powers did in their fashion represent at least a potential evolutionary change,--but it could never have happened.

Nor was there any room for compromise so far as the Allie were concerned: the governments, the political regimes, of Germany and Japan had to be wholly obliterated. Also, to bring this back to films, the changes in the way movies were made between 1918 and 1939 were vast, with the addition of sound adding greatly to the feeling of realism in film. I find that First World War movies, especially but not exclusively those made before 1940, tend to nearly always feel somehow wistful about the era they're depicting, while World War Two films, those dealing with combat, the ones that emphasize action, whether on land, at sea or in the air, came to constitute, broadly speaking, a genre unto itself, and one that remained popular for decades after the war, like westerns or swashbucklers.

Yes, The Guns Of August was big as a film and as a book.

The first war, and various aspects of it and its aftermath, also turned up in movies of all kinds, from Jules et Jim to Nicholas & Alexandra.

Gallipoli is pretty good although there really isn't much to the actual battle.

A modern film about the campaign against the Ottoman Empire would be stupendous. The Mesopotamian campaign was full of blunders by leadership and led to the capture of an entire British force. The Siege of Kut was a travesty.

Of course, don't forget about Lawrence of Arabia.

The Lighthorsemen is another good film about the war against the Ottomans.

I wish film studios would re-master the Yugoslavian film "Fraulein Doktor" (w/Suzy Kendall - 1968) or remake the damn thing already...

It is an outstanding WWI film with grim scenes of trench warfare...