I'm more worried about the increasing US national debt.
China already control most of US debt, so if they wish they can hurt US, but they will hurt themselves too.
But their economy is decelerating now, so maybe if they fall they would like to bring others together
That is right. China is in a bad situation actually. The Chinese could not do anything that hurt the USA because most of their exports go to the States. So, China is dependent on the USA and the USA is dependent on China as their biggest creditor. I am sure nothing will happen after 19th or 24th April, 2016.