I recently watched "Darkest Hour", the biopic about Winston Churchill in May 1940. I'm usually not a fan of biopics, which are oscar-bait at best and boring distortions at worst. "Darkest Hour" begins really strong, but it falters in the last third, falling victim to the problems it shares with many other biopics.
Usually, the problem is the sheer timespan. Compressing a life in a single movie is a daunting proposition, and seldom are scripts able to pay it off, especially since real life tends not to neatly fall into narrative arcs that make for good storytelling.
This, in turn, leads to overdramatization of certain moments on the life of the person, of cleaving throught the people dividing them in heroes and villains, and to boil it down in one final moment. This works in stories, but real life does not work out that way.
In fiction, this isn't a problem. You can go for leitmotifs there, for themes, for big emotions. You can even get away with this in historic situations by infusing fictional characters, which is what most movies opt to do. But whenever you start going into the territory of real persons, telling their "life story", those problems emerge quickly.
This leads to such badly advised decisions as making Margret Thatchers life about discussions with the ghost of her husband (because why wouldn't a movie revolve around a man, amirite), Johnny Cash's life story ending rather anti-climactically and arbitrarily with the marriage proposal to June Carter, with the urgent need to invent "good Nazis" for "Downfall" to pose a foil to the bad Nazis Hitler surrounds himself with - or to Winston Churchill winning the war by riding the Underground.
I know this isn't what "Darkest Hour" was going for. But given that we know how it will play out, they needed to insert some drama into this, and they needed to tie it to persons. This is where they positively smear Lord Halifax as a traitor who wants peace with the Nazis, or at best being an utter fool, to give Churchill a foil, and to introduce the English king as deus ex machina to give Churchill the idea to ride the subway and ask the people if he should give up after his war cabinet and the military propose doing so.
This is problematic for two reasons. One, the idea that the elites are just too stupid to grasp the truth the common man and woman on the Underground are able to deduce just by their common sense is as stupid as it is dangerous. And second, Churchill gets the belicose statements of resistance by rhetorically manipulating first them and then the Commons into declaring for him, which is a feeling with a rather short life span under normal circumstances.
Yet here, aided by a swelling score, it is the height of his triumph. Not his determination, good analysis, cool-headedness and the support of a great coalition of people doing their jobs well, but rather a whim and a random subway ride. He then holds his famous "fight them on the beaches"-speech, and that's how he won the war, and the closing credits inform us that te villains of Chamberlain and Halifax soon died and were send off overseas, respectively.
Nothing of this is remotely true, and to make this point, imagine a movie in which Goebbels takes a subway ride through Berlin and is motivated by a swelling score and the common people of Berlin being sensible to declare Total War. It's absurd. And obviously, the rousing declaration alone doesn't win conflicts, be it wars or political strife (thank Aaron Sorkin for planting the notion that one speech resolves every conflict).
But you wouldn't know that from "Darkest Hour". So please, instead watch "Dunkirk". It's the better of the two, and it manages without even getting a fabricated villain character in, which is more than you can say about the deplorable script of "Darkest Hour".