if China really wanted to wreck the US all it would have to do is say two words... "Sell Dollars". The Chinese are holding the second largest amount of dollar reserve assets of any foreign country. If they dumped all of those on the world market, the dollar would tank, interest rates would soar, inflation would return to double digits, and the standard of living of every joe shmoe in the US would go down the pooper.
And China would lose it's grip on the US, throwing away it's most significant bargaining chip and 'trade war' weapon.
Our economy has weathered worse threats than this one and emerged stronger and wiser for it on the other side.
They don't scare me at all.