Considered an Anti-War film, or a Pro-War film?
I know that this story can be argued from both sides of this fence, but I feel that the film Sergeant York was intended more as an Anti-War account than that of one that promotes war.
Initially, Alvin York himself is portrayed as a misguided man that spends his time making trouble and stirring up violence. Several accounts of aggressive action are noted in his bar fight on the Kentucky border, his attack on Zeb when competing for Gracie Williams' favor, and his rage inflicted reprisal to the landowner that sold good farming land to Zeb instead of Alvin despite a recent contract, and the fact that Alvin did come up with enough money.
But when his emotions smoldered at a local bar and he rode off in a storm to commit a violent act he likely would regret, his rifle was struck by lightning, himself and his mule left intact. He took this as a sign from God that he shouldn't do what he originally intended, and became convinced of a higher power because of the fact he was still alive despite being struck directly by lightning.
Since this point, he is shown making amends with the people he felt he wronged through his misguided action, and it is shown that his hard luck starts lifting as he starts actually getting what he aims for as well as ends up happier for his endeavors.
During the draft for World War I, his application for draft exemption and the following appeal were denied. In the military training camp, he was goaded and talked down to for being a conscientious objector to the war, I.E. someone who refuses to support a combatant organization because of conflicting personal views. But then despite this, he was talked to by the commanding officer of the training camp, and it was explained to him that they were not going to war to spill blood. They were going to stop someone who did not share their peaceful ideas, and to protect people who couldn't fight back (civilians and families). Although conflicted, he participated in the war willingly under the premise that it was to save lives by stopping those that were killing.
It was by this philosophy that he killed minimal Germans, instead taking as many of them prisoner as would surrender. He employed the help of the German trench commander to force surrender on more German troops. By this method, he avoided killing the hundreds of Germans he instead spared as prisoners. Additionally, York argues to his own superiors that in doing what he did, he saved hundreds of other soldiers from dying from the machine guns being used by the Germans.
Even during post war celebrations, when York was offered large sums of money to be part of advertising and showcased as a celebrity, his reply was that he didn't do what he did for fame, money or glory. He did what he did to save people's lives. People he went their with died doing the same thing, and he wouldn't be a part of selling the deaths of the war for money.
Consistently throughout the movie, especially during times of great conflict, the film Sergeant York portrays an anti-war belief even in the face of imminent killing. Instead, it focuses on the prospect of preserving as many lives as possible, even the German's, as was demonstrated by York in the war.
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--"That Which Issues From The Heart Alone, Will Bend The Hearts Of Others To Your Own"