The military might well have difficulty openly assimilating male soldiers who want to have sex with other men--the culture of many military institutions runs on sublimated hetero impulses (something dramatized effectively in the movie Jarhead, among other places). Marines use the idea of "Jody," the mythical civilian back home who is screwing your girlfriend/wife, to get soldiers committed to battle. The trick might not work so effectively on Marines who are less hot for the women back home than the men in their own units. No doubt other tricks could be developed to motivate gay Marines. The point isn't that gays shouldn't be able to openly serve, but that it's not a simple adjustment to make. Less simple than opening the Marine Corps to all races.
So there ya go. Kaus believes we can't integrate the Armed Forces because doing so would require slight adjustments in motivational rhetoric.
in any case, given the modern responsibilities of the army, Jody tricks really aren't an issue. Marines are rarely herded into trenches and given pre-engagement pep talks these days. This isn't 1942 and we don't tend to fight many land-based wars with non-mechanized units. And, frankly, the last thing we need are soldiers in charge of massive weaponry to be overly pumped up. Given the firepower at troop disposal, battlefield calm is something to shoot for, not protect against.
