Balance issues… Dardanelles should always be closed… NOs favor the Axis, hands down.
Something not in the rules, but a very simple House rule our group uses for both balance and just plain fun…
90% of the time, Japan nukes the Flying Tigers in China on turn 1 before the Allies get to make a single move with them. They are basically placed in a “please kill me” position.
Our group always allows the Allied player the choice to place the Flying Tigers anywhere they want within China on the initial setup… it’s a very minor concession both for play balance and strategic fun.