The point is that this is a dispute between two American companies and their respective patents. We are basically a free market as far as patents go. If I own a patent on a given product or component I can have it made wherever it is legal to do so. The foreign source for the chips is irrelevant as this is not a dumping case, i. e., attempting to corner a market with cut rate prices. USA patent law should take precedent in this case.
That, and Qualcomm was busily making partnerships with people like Kyocera and Samsung to make the infringing chips overseas...
It may be a dispute between two US companies but one of those companies is involved in importing a product that violates a patent. There is no reason the law should not apply. Otherwise, a foreign entity could dodge the law by buying a token front company in the US.