Why does the US allow China to block so many American technologies? To me this is almost akin to banning the import of American cars, or any other domestic expo

Why does the US allow China to block so many American technologies? To me this is almost akin to banning the import of American cars, or any other domestic export. The United States has such a huge trade deficit with China, you would think the government would fight for whatever little "export" they can get, whether it be a technological export or otherwise.