In WW2 we initially had no sources for rubber. It didn’t take TOO long to come up with a substitute, which we still use today.
But we also lost out source of hemp, after the Japanese took the Philippines. My father worked in a factory that made a substitute rope from sisal fiber. Raw, nasty stuff that was weaker and tore at the hands of sailors.
More to the point, after the Allies took Morocco, Germany had no source for nickel. One result was that the valves in their aero engines lasted only a few dozen hours before they had to be replaced. Ditto the turbine blades in their otherwise advanced jet engines. This made a huge difference when it came to winning the air war in Europe.
bkmk
“In WW2 we initially had no sources for rubber. It didn’t take TOO long to come up with a substitute, which we still use today.”
Maybe we have stuff now, but not in one of the videos that I saw years ago. Back then, they were trying to recycle rubber, trying to reduce reliance on rubber, and trying to produce artificial rubber. But nothing was effective and we were damn lucky to get some plantations in Asia early in the war.
...and rubber is likely easier to substitute than virtually anything on that list.