[nitwit005]

Assuming there is a single source, and that rival country is completely determined to stop you from getting any of it, instead of selling it to make money as normal?

More commonly they'd just put a tariff in place, which is likely cheaper to pay for than a war and occupation.

[erkose]

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

[nitwit005]

I understood the example, but speaking in generalizations at this point.

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-...