This is a very big deal. China is hypersensitive to any official contact, military sales, bilateral deals between Taipei and Washington. To give you an example: In 1996 when Taiwan's former president went to the U.S. to receive an honorary diploma from his alma mater, China responded by launching missiles into the Taiwan Strait.

I fear Beijing will do something similar to save face/show strength. It also sets the stage for China not being able to trust the United States to behave within established foreign relations norms.

Watch this space.