If nations such as germany, japan, and the united states prohibited international trade in automobiles, a likely effect would be that

The automobile industry would suffer a dramatic decrease.

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.