1917

https://www.showbiz411.com/2019/11/23/oscars-2020-last-big-movie-to-screen-sam-mendes-extraordinary-1917-best-war-movie-since-private-ryan-iwo-jima

I think I'll see this. The only thing that looks a little "off", just judging by the trailers, is that the scenes look to "clean", even antiseptic; the uniforms, the conditions in the trenches, etc. WWI wasn't like that, believe me !

https://observer.com/2019/12/1917-review-benedict-cumberbatch-sam-mendes-rex-reed/

I'll see this for sure. Everyone is giving it good reviews. WWI has been of interest to me for awhile because it is the one major war in modern history that started for no good reason and resulted in so many unnecessary deaths. It started simply because several countries decided to 'honor' various related treaties and agreements  and it snowballed from there. If the archdukes assassination had been not responded to by the major powers of the time and let Serbia and the Austro-Hungarian empire work it out between them, then very likely nothing would have escalated. Of course the map of Europe would have remained very different than in reality and what the A-H empire might have resulted in later on in the 20th Century is a good subject  for alternate history S-F.  

https://en.wikipedia.org/wiki/World_War_I_casualties

https://en.wikipedia.org/wiki/Causes_of_World_War_I

Here's a bit from the Variety review:

How do you define heroism? For more than a century, movies have shaped our collective idea of the individuals and actions that qualify, often making the word appear out of reach to ordinary mortals. Now, along comes Sam Mendes’ “1917” to smash those assumptions, revisiting a day in World War I when two ordinary British soldiers — Blake (Dean-Charles Chapman of “Game of Thrones”) and Schofield (George MacKay) — distinguish themselves by undertaking a mission for which neither is the slightest bit prepared.

Heroism reflects courage, of course. But that’s not the same as an absence of fear. There are scenes in “1917” when audiences will see Blake and Schofield panic-stricken, terrified and even in tears. Their errand calls for bravery, and yet, at times the pair can’t help but second-guess their decision to deliver a message that could save the lives of 1,600 fellow British soldiers. To do so, they must cross the battlefield in broad daylight, infiltrate booby-trapped German bunkers and confront the enemy face to face. One can hardly fault them for being afraid. If anything, the tension they feel makes the characters more relatable.

Heroism is about doing the right thing, but also about doing the thing that no one else wants to do. To a certain degree, it’s about luck, for many a heroic act has been thwarted by chance, leaving no one to acknowledge the sacrifice — although as “1917” demonstrates, glory plays no part in heroism. “Nothing like a patch of ribbons to cheer up a widow,” one officer cynically remarks. Drawing from war stories shared by his grandfather Alfred, who fought in the trenches, Mendes brilliantly re-creates the terrain — physical and emotional — navigated by its unlikely heroes, seen peacefully napping beneath a shady tree in the opening scene.

In the two hours ahead, Mendes will follow the pair into the realm of nightmares, depicting WWI as we’ve never seen it: simultaneously horrific and beautiful, immersive and detached, immediate and impossibly far removed from our own experience. These paradoxes define the unique sensibility of “1917,” which isn’t necessarily “better” than such iconic WWI films as “War Horse” and “All Quiet on the Western Front,” but different. Mendes has found an original approach to a familiar subject, refreshing events from a century ago in a way that looks, sounds and feels absolutely cutting-edge.

https://www.thedailybeast.com/1917-star-george-mackay-on-filming-the-best-war-movie-in-over-20-yearsin-one-shot?ref=wrap

It's not filmed literally in one shot in the sense that the camera was turned on, all scenes were filmed, and then it was turned off. The scenes were filmed in segments as in any production, then in editing it was made to seem as if it was one continuous shot. It doesn't detract from the film of course. This is explained in detail in a You Tube doc.