The war film may be regarded as a sub-category in the historical film since it deals with a past event, here, it is a military engagement.
Like all history it is an interpretation of the past based on the preoccupations of the present.
A major part of the world’s war films have dealt with WWII since so many countries were involved in or affected by that war. Another fact ab out WWII is that it was a war which resulted in a complete victory for one side over the other making interpretation easier: Everything about German doings came out into the open and became part of acknowledged history worldwide. This clearly demarcated heroes and villains, which has not been true of most other wars.
WWII is therefore emblematic of the fight between ‘good and evil’ in a way that WWI is not. The approach of the same film-maker to the two wars can be quite different.
Steven Spielberg’s War Horse (2011) set in WWI is anti-war, and is even-handed in its approach to the two sides while his Saving Private Ryan (1998) is patriotic and deeply anti-German.
Most war films take sides and are essentially nationalist exercises, which would be true of an Indian (anti-Pakistan) war film like The Ghazi Attack (2017).
Given the above factors it may be surmised that most war films appear when the national mood is relatively upbeat but this is not always the case. Christopher Nolan’s Dunkirk is an illustration of a film that does not follow the patriotic model, particularly, since the Germans are not demonised. What the film does instead is to rely on its creation of what the physical experience of Dunkirk was like. The United States and the United Kingdom were allies in WWII and describe many of the same experiences in their respective war films. But what is striking is how upbeat American war films generally are about patriotic values and how downbeat Dunkirk is – although it strives to present itself as an ‘affirmation’.
A motif which recurs in the film is the unwelcome presence of the French on British ships. The first time this happens a French soldier is told that there is passage to England only for British soldiers. On another occasion a soldier who does not speak English is discovered on a boat and taken to be a German spy - until his French nationality is learnt. The immediate response of the others is to call him a ‘frog’- a familiar term of derision directed at the French. This lack of empathy for a military ally is not often encountered in war films and one is tempted to associate it with Britain and France having a rather cold relationship today, especially after Brexit; in fact there has been much greater solidarity between France and Germany, who were wartime enemies, in the recent past.