The chemicals used to manufacture Ice most likely come from the US which is the reason why the US banned illegal exportation to Mexico. It's an important substance most likely used for flu treatment drugs which can then be transformed into Meth.
Mexicans' way of production is highly-advanced and considered the best in the industry. Would you rather import chemicals from the US legally or would you rather source them from thousand miles away?
It is highly unlikely to manufacture actual meth in China, as you will get death sentence easily. Most drugs used in China come from the Tri area.
