The Swarm Tactics card says neither may , attack or action . Using it is not optional.
1) If all ships you can use it on have a higher PS than you, do you still have to use it? I'm afraid you have to. Is this correct? That seems rather odd to me.
2) Assume there is no friendly ship at range 1 at the start of the combat phase. How do you proceed? The card has to be used after all. Mandatory meets impossible.