Japan needs to take Hawaii or Sydney to get a VC win, thats all you need to do with the US in the Pacific - stop either of those from happening, spend the rest of your resources sending the US into N.Africa, and once big enough Rome. Italy is going to have to choose between pulling back from taking Egypt or taking the chance the combine UK/US forces take Rome as early as round 5/6
another example of this in action is attacking an enemy sub. He might (and probably will) submerge, but its up to the defender so the attacker needs to send enough hardware to the sz to win if the enemy defends.
What stops US or UK placing 4-5 fighters in Gibraltar. Each would roll a 2 vs a 1 the escorting fighters if any(lack range i think) might get. Each Bombing raid would cost the attacker 1-2 bombers from defending fighters before you roll AA.
