The answer is the us and great Britain led to an embargo against oil destined for japan
The united states eventually stop supporting South Africa because : South Africa began taking arms and funds from the soviets.
Back then, United States was in the middle of cold war with the soviets union, and this showed that Soviet has implemented its influence in south africa
Hope this helps
The two ways the US government financed the war effort was taxes and tapping into americans personal savings which is bonds
Government regulation might be used to facilitate competition
