[angryprofessor]

It's true that we were the world leader once upon a time. From the 20's to the early 40's, we had a major competitive advantage: our factories didn't explode much, whereas European and Japanese factories did. In the late 30's and early 40's, there were also trade barriers (http://en.wikipedia.org/wiki/U-boat, http://www.navy.mil) preventing the US from receiving Japanese and European exports.

However, in 1945, Europe and Japan figured out how to build non-exploding factories. The trade barriers were also removed. We retained our competitive advantage for some time after that, since it took them time to build up an industrial base.

But it is silly to expect us to be world leaders to the extent we were back then. That epidemic of factory explosions was a one time occurrence.