The word "troop" was used in reference to an individual or group interchangeably when I was in the army.
This brings up a point with me that seems to run through this entire thread and that is "learning to differentiate between the military as a whole, and what the individual soldier is responsible for". Time and time again on the board, I see a lot of people railing against what the "military" does and sometimes it is not clear whether you're talking about the soldiers who are individual, REAL people (who could use a little empathy and certainly are NOT mere numbers. Please, those who served get enough of that from their superiors in the military). I would say that in a lot of what the soldiers are called to do, they rarely have a choice but still seem to answer for later and are victims to these generalized theories of the "monday morning generals. As if!!
Most soldiers don't have a sense of loyalty to the ARMY as a whole but to their individual unit and rarely have the perspective of what's happening in the army "as a whole" but only what they need to do to get by. When they return, however, they're seen as the target for what evils the what the military did, as a whole, "over there". Whether this leads to suicide in some cases I cannot say (it depends on the individual, certainly) but I can't see where it would help.