Simply put, is it possible to use Recall offensively to draw another unit from anywhere on the board into a battle that contains an Arbiter? Here is the card's description:
"After moving units during a Mobilize order: You may move on of your units from any planet to any area on the active planet that contains one of your Arbiters."
It seems that this is possible. First, the card says after moving units and resolving a battle is after moving units. Secondly, it says any area and not just a friendly area. Anyone know the official ruling?