If China is forcing U.S. firms to hand over technology, why hasn't the U.S. taken China to the WTO and filed a complaint?

Question

The U.S. keeps saying that China is forcing its companies to hand over technology, but then if it's the case as they say, then why didn't the U.S. take China to the WTO in order to complain about it? The U.S. has won the majority of the complaints it filled against China, so why won't the U.S. use the WTO? Did the WTO rule against them in the past? What happened? We only get one side of the story in the West.

Answer 1

The EU has started a WTO case against China (DS549) on that. It's still in the consultations phase. The US (on 21 January 2019) and some other countries, including Japan have joined it.

This concerns the request for consultations by the European Union on China – Certain Measures on the Transfer of Technology, circulated on 8 January 2019 (WT/DS549/1/Rev.1). My authorities have instructed me to notify the consulting Members and the Dispute Settlement Body of the desire of the United States to be joined in these consultations, pursuant to Article 4.11 of the Understanding on Rules and Procedures Governing the Settlement of Disputes. The United States has a substantial trade interest in these consultations. They concern certain measures of China related to the ability of foreign intellectual property rights holders to protect their intellectual property rights in China on which the United States has also requested consultations (WT/DS542/1). The consultations also concern measures related to the access and operation of foreign investment. By 2017, the U.S. foreign direct investment (FDI) stock in China exceeded $256 billion.

It's not too clear to me (yet) what US's own case (DS542) is mainly about, which is mentioned in the letter quoted above. It does say this among other things:

China denies foreign patent holders the ability to enforce their patent rights against a Chinese joint-venture party after a technology transfer contract ends.

So it seem more tangential, i.e. the complaint is what happens after the joint-venture ends. In contrast the EU complaint (which the US has joined consultations) is more squarely about how that transfer happens in the first place (from the updated version of the complaint; 8 January 2019):

Through its domestic legislation, China conditions the right to invest in China, including the possibility to access and operate in the Chinese market by foreign investors, foreign invested companies and joint ventures between foreign and Chinese companies, upon performance requirements, including in relation to the transfer of technology and the conduct of research and development in China, contrary to China's WTO obligations.