What I meant by internal is changes that in the literature on trade are referred to as behind the border, changes that have to do with.... First of all, Canada is a confederation, and therefore it's a somewhat difficult country for others to negotiate with. For example, you negotiate with Canada and you sign with the federal government an international free trade agreement, and then you figure out that what you signed doesn't really mean much, because the provinces will not allow you to provide services across their border. If you are trying to provide architecture or engineering services, which are very important, for example, for Asian investment in Alberta in the oil sands, you cannot do it unless the provinces in which those investments are allow that foreign provider to come through.
Those are changes that Canada would need to make if it were to receive more investments from abroad, which is, for example, the target that those countries in the Pacific Alliance have. They have the advantage over Canada that they are either unitary countries or are federal in name, as in the case of Mexico, but much less federal than Canada.