If Japan had won the war in China by May 1940, would it still have struck south?
Short answerProbably yes; after consolidating China, Japan would still seek the oil and raw materials needed to reduce its dependence on imports.
NotesA victory in China by May 1940 would first leave Japan wanting time to consolidate its position. It would not remove the resource motive for advancing south. Fuel, minerals, and other supplies were sought to reduce dependence on imports. The counterfactual therefore changes the sequence of expansion more readily than the underlying strategic demand for resources.