OK so I was thinking about this this morning. In the Vietnam war American GI's using their special military alphabet (Not in alphabetical order: Alpha, Whisky, Foxtrot, etc) referred to North Vietnamese combatants as Charlie. Charlie is obviously the letter C in that alphabet.
Today, enemy combatants in Iraq, Afghanistan are (from what I have seen) referred to as Tangos. I don't think I have heard of them referred to as Charlie.
Were VC forces called Charlie because they were communists and communism starts with a C? And are enemy combatants called Tangos because they are terrorists and terrorism starts with a T?