well, reasons for civil wars vary, but really, it all comes down
to a difference in political ideals or mere power struggle.
The trouble with the army is that you're NOT supposed to choose a
side; you're supposed to take orders, not unlike a waiter in a
restaurant. Hence the chain of command thinggy yah?
hence the irony of "the thinking soldier"
I think most saf soldiers, in the event of a war, wouldn't hesitate
too much if the threat was external. Troubles ring when there's a
possible conflict of personal interests vs direct orders.