It's difficult to know how much of what Trump says at the moment is something that he means to follow through with, and how much is just something that he thinks will sound popular with an election just around the corner.  I'm sure he thinks it looks good to sound tough over China, just as the Chinese like to sound tough over America. But a lot of it is empty posturing, and it can be hard to differentiate between this, and threats that are actually followed through on.