One clear takeaway from Chinese President Xi Jinping's Jan. 17 speech at the World Economic Forum in Davis was that U.S. President Donald Trump has him on the defensive.

Xi delivered a minor surprise by passionately backing free trade in a rebuke to the protectionist platform that helped Trump get elected. "No one will emerge as a winner in a trade war," Xi said. What he forgot to say is that those conflicts are never officially declared, and China has been in one for years.

It's one thing for China to use its cheap and disciplined labor force to grow rapidly through exports, most of which directly and indirectly end up in North America and Europe. It's another to dump excess steel, aluminum and other products on world markets.