After a few Axis victories with the Cairo and Suez Strategy, I think the counter to this would be to make sure that France does not fall early in the game. Keeping France in the war - at least up until the Spring of 40' (or maybe even summer) ties up Germany (and Italy) so they do not get a head start in Africa if they choose that route. This seems to be critical, as there is a lot at stake in Africa. If the Allies lose control of Africa, the war will be more of an uphill battle for them.