How did the United States respond when Asian natural-rubber supplies were cut off during World War II?

When Asian natural-rubber supplies were cut off following Japan's entry into World War II in 1941, the United States initially attempted to cultivate alternative natural sources, such as the guayule shrub. However, these efforts yielded little success.1

The United States responded more effectively by rapidly developing a massive synthetic rubber industry. This initiative was established almost overnight, eventually achieving a production capacity of 800,000 tons per year. While the U.S. synthetic industry experienced a sharp decline once natural rubber became available again after the war, the development of superior and more uniform synthetic materials by the early 1950s ensured the long-term viability of the industry, eventually leading to synthetic elastomers surpassing natural rubber production in the early 1960s.1