I think the psychological perspective is that because there are less occurrences of the types of things that go on in Afghanistan, the unexpected actually cause more tension, in some sense. It's not to say that if you're driving in a LAV down a road in Afghanistan you're not under tension as well, clearly.
I have never been in a firefight as a peacekeeper, which seems to be a common occurrence in Afghanistan, and it certainly was during World War II. But I was mortared as a peacekeeper when I visited UNIFIL on the Lebanese border, at the time I was serving in Egypt. I actually was mortared when I was in Camp Pearson. So those things happen.
I don't in any way try to compare peacekeeping or peacemaking missions with what is clearly a war situation—whether it's called that or not in Afghanistan—and where there is an actual hostile interface of fire all the time. Peacekeeping operations are not normally like that. But then again, Bosnia was another situation where there were open firefights—