They wont be able to set us back that much. Lets be real, the US COULD set china back to the technology of America in 2015. I'm pretty sure if China got even close to the GDP per capita of America in 2015 it would have long been game over for that empire. Either way, I'm pretty sure the liberation movements in the US will offer a meaningful distraction to that goal.
There was already 14nm chips in 2015. If a total semiconductor embargo is imposed, we will be looking at 2005 or even earlier.