So here is my 2 cents on the document: Disclosure: I only skimmed it.
First, this document is a 2009 report investigating whether or not to impose tariffs on tires made in China. The commission recommended that tariffs be imposed. One of the justifications was that tires produced in China are substantially the same as tires produced in the US - and the quote FastEagle posted is addressing that point. Please note: It is NOT a technical analysis. It is trying to address any potential argument that the tires are different.
I agree wholeheartedly with their assessment.
Second, I reject any argument that this report is somehow not applicable to ST tires. ST tires can be produced in the same plants as P and LT type tires - and out of the same materials, utilizing the same equipment and workers. What difference there would be are detail and DESIGN related - that is the details about what materials are used where. An example of this is the use of nylon cap plies.
In other words, ANY tire manufacturer who produces LT and P types COULD produce ST type tires.
Third, this document does not address - nor can it address - "quality". (and in this case, I am using the term to mean consistency from individual product to individual product AND faults in the production process - commonly known as "defects". I am NOT using the term to mean the performance of the product - or how well the tire is designed.)
So in one respect, the document says it is POSSIBLE that the quality of Chinese tires is the same or better than tires produced in the US, but the report doesn't say that they ARE. It only says that tires produced in China would be purchased and used EXACTLY like tires produced in the US - thereby hurting the domestic producers of tires.