"I'm not sure. The excess availability of cheap surplus energy has always meant that all that surplus energy is used. I can't think of a civilization that has resisted the temptation to grow (size, rate, complexity, etc) using available surplus energy."

Have you ever heard of Edo Japan?

They changed when someone sailed up and started shelling them with modern explosive shells.

Commodore Perry. He demanded they trade and grow.

He was American :)