Pretty much.
Let's say that the impossible happens and through his sheer power of Jedi mind tricks, Donald Trump outmanouveres Kim Jong Un and collapses the entire North Korea regime.
Are China going to be happy to let that be replaced with a pro-US government right on their doorstep? F**k no. They'll give the order and they'll replace Kim Jong Un with another pro-China regime before the CIA ever could. I've no doubt they have the plans in place already.
That's what Trump fans don't get: China is the only player in this who cannot lose.