If the commies had taken over during the nineteenth century, forget about internal combustion engines and their descendants such as automobiles and aircraft, or spacecraft or computers. The “present (would have been) dominat(ing) the past” too much for any concept of the future to ever have coalesced. Technology is going backwards already—no more SSTs for example.
They could definitely kill the golden goose.
But for the last 20 years, we have had rapid technological change that seems to be continuing (as far as I can tell!) — widespread internet, internet commerce, smart phones, revolution in media delivery, DNA analysis, genetic engineering, manufacturing techniques, drone aircraft, etc.
And we still have competition between nations, which drives technological advances.
Answer: Electric light bulbs.