Kubrick’s first relatively big budget film, seen in some circles as anti-war which is overly simplistic. Kubrick doesn’t make such blanket statements. Rather, it’s an examination of courage and cowardice while being totally realistic about 20th century warfare and its corruptions.
It says anyone on any side of a conflict over power can be corrupt and in modern warfare it tends to be the commanders, politicians and statesmen chasing glory (quelle surprise). It also points out the stupidities of World War I in particular, a war which commenced over a trivial, childish disagreement (in the film, the main point of conflict is a target called “The Anthill”) and snowballed into a full scale global tilt for power. In addition it suggests the Allied powers at the time were at least as corrupt as their enemies, using the French army as a “scapegoat” but depicting them with American and British actors speaking fluent English/American.