@boothead: As somebody who's never been in the military (drafting for military service was suspended just before my number came up) I'm curious. Does the level of engagement and team cohesion you speak of only occur in, or afterwards derive from, combat situations, or would it theoretically be possible to recreate these levels outside a military context as well?
I think the key element is 'shared hardship'. Personally, I didn't see combat, but military life in general sucks; doing a lot of stupid stuff at the whim of others. I think you see this in other areas of life as well, sports teams, project teams meeting tight deadlines, etc...
It's really to do with the incubation of a very strong shared culture and shared experience. For example the Royal Marines has a history going back 350 years, a shared language (google jack speak), and the longest and arguably hardest basic training in the world.
I believe it is possible, albeit in a slightly different form: elite sports teams and groups of people tied together with a strong shared purpose can get there I think.
edit and yes, as marktangotango says - shared hardship and knowing you can count on the next guy because he's been through what you have and hasn't broken either is also key.
