Political Strife - There were two different kinds of strife happening in this way during the film, 1) The obvious tension and strife between two empires at war, the British and the French, and 2) the emerging strife and tensions between the British Crown and its soldiers and the colonials who are not blindly loyal. While no Americans were really talking about independence yet, the differences between these two peoples and their views was made very plain in the film. For example, think of the time when Duncan tries to recruit troops for the militia, or when those troops try to obtain terms from General Webb.
Human Suffering - Obviously, it is a war, and of course the soldiers are suffering, but there were also many civilians caught in the crossfire. There are those who are killed on the frontier settlements by a war party of Huron, and those that are massacred along with British troops by Magwa's men. We also have the individual suffering of the characters as they struggle to escape Magwa's desire for revenge.