Uh oh...
If China severs the peg to the US Dollar, that will be one of the key road blocks to the US moving to a policy of printing it’s way out of it’s debt. Look for inflation to rise if this happens.
If the yaun goes up, less Chinese exports and more American imports
But I think the Yuan collapses. China is a basket case right now (one example - their “stimulus” package is about an order of magnitude higher than ours and run much less efficiently). A free floating currency might crash the yuan.
The peg will stay in place until both are fully accomplished. The US debtor nation will do nothing in the meantime.