The war for Europe was arguably won in Africa well before any major advances happened in either of the European fronts.

The North African campaign combined with the supplies the US has sent to the Soviets was pretty much the only reason why the Soviets have won on the eastern front.

The Axis and specifically Germany were over extended in Africa and Africa pretty much took all the fuel and air lift capacity Germany had at the time.

The Italian campaign was the nail in the coffin for the Axis in Europe well before D-Day.

And that is if we can ignore the pacific theater altogether.