The concept of "free trade" is tenuous, unfortunately countries will will try to leverage an advantage in their favour. This is now happening with the US and certainly would apply to China. I agree with the article Canada's focus should be on the US they are our most important trading partner. I believe caution is warranted with China as they will pursue their own agenda & objectives. 

It's time to give up on the notion of open free trade, it's something that one can strive for but never fully achieve. Countries will at some point put their national interests at the forefront. This is what the US & China are doing. Even though they are two of the largest economies we should not cave-in for their national interests. There are other countries in the world we can trade with.