[Mobhack]

There is no concept of "North" or "South" etc - if a scenario designer wants to put an annotation on his map as to where North is for this battle, then fine.

Otherwise there is "Left side" and "right side" of the map, each side deploys on one or the other, and plays horizontally across the monitor screen. Some scenario designers have tried a "vertical" battle but the game is not designed that way - retreaters go for their monitor edge, arty comes in from it, AI path-finding and deployment (in random battles) is based on the left-right paradigm.

So if the USA are deployed on the RHS against say a WARPACT force, it really does not matter much at all other than "player expectations", perhaps, based on some idea that the RHS is "East" - and in any case, in war they may well be attacking from that side say due to having encircled the enemy or whatever.

And of course - the deployment map side is not always fixed, especially against guerilla type opponents. Israeli V PLO and USA v VC are such (as far as I recall). Also battles v Mujadeen, IIRC (not digging into code to find out).