The original strategy was no secret what Japan was doing. It was hauling units back and dropping serious money on transports. The idea was to get them next to W. USA/Panama or one space away so you could close the Canal and take W. USA before America could build enough to stop you. Meanwhile, the Germans had to be in SZ 91 with some transports of its own, it was like 10 transports and units in Gibraltar./SZ 91 so they could attack E. USA or E. Canada. That made it so America lost Panama and W. USA but could build enough to stop an E. USA attack but not enough toliberate W. USA and E. Canada.
It was almost unstoppable. Or rather, I have never seen anyone stop it. (Putting that disclaimer on so that Jimmy/Jim dont start threads about how to stop Operation American Eagle, etc.)