I provided context for this, WW2. The Allies were cut off from the natural rubber supply of Southeast Asia at the beginning of the war. You can read more about it here: https://en.wikipedia.org/wiki/Synthetic_rubber
I would note that the US struggled to produce rubber in the Phillipines, so they didn't exactly get that out of the occupation: https://www.foreignaffairs.com/articles/philippines/1926-07-...