Diversity: The U.S. Military's Not-So-Secret Weapon (

A pretty good summary:

> Since 1783 and the end of the Revolution, United States society has struggled with the idea of who should serve in the armed forces, and why. The arguments are usually entirely unconnected with the realities of military service and instead focus on social norms, or the perception that the military is being used as a vehicle of social change. It is expediency of the dire hour which usually causes Americans to stop wringing their hands and realize that strength lies in diversity.

(The article is very U.S.-centric, but "who fights, in what roles and circumstances?" was a regular issue back when building pyramids was a trendy new thing.)