If Germany-Italy were one country and if it should attack Poland—then any amateur war-gamer would know what Britain-France must do. Britain-France must destroy Italy. Thus they would deliver a shattering wound to Germany-Italy, become masters of the Mediterranean from end to end and able to bring help to Poland and to the entire Eastern Front.
But Germany-Italy is not one country. Suppose Germany attacked Poland and Italy stayed out. Britain-France could not then beat Germany by hurting Italy, and Britain-France could not be sure of being masters of the Mediterranean because Italy...