Greg Smith said:A player may ultimately be forced to not send any forces. If a player wins and decides to attack target X, only to find the other players attack his targets Y & Z, he may decide defending Y&Z is a more sensible option.
Well that brings a question, it seems that you know what your opponents will do before fighting.
Maybe we misunderstood the rule but when a player declares an attack we resolve the fight and then the next player decides what to do.
So if you attack X when you discover Y is attacked you've already fought so you're having less options. And when Z is attacked it's the same you've got less and less ships.
(playing this way that's why we allow a "pass" option so the player with the best init may play last waiting for others actions)