I have been told the following. Please let me know if it's correct.
"If the active player chooses not to attack with their characters, then there is no 'Attack Step'. Therefore the inactive player can't use Global abilities that they might have been saving to see if they'd need for the attack step. Thus losing all opportunity to use Globals before the beginning of their turn, when all the Energy in their Reserve Pool moves to their Used Pile."
What I'm not sure about is, it seems like there is still an "Attack Step", the active player just didn't chose to attack during it.
Let me know! Thanks!