Perhaps the more interesting would be what didn't happen. There was little or no cooperation between Germany and Japan. For example - why didn't Japan declare war against Russia? What about a load of U Boats going to Japan to operate against the Americans There didn't even seem to be technology transfer - I am sure the Japs would have liked the MG 42 and the Germans the long lance torpedo. I suppose it was difficult to communicate or move goods, but it does make you wonder.