Canada has always been and always will be highly dependent on international trade. In relative terms we're a small country and can't sustain our standard of living without being able to tap into foreign markets in one way or another. Anything that puts that at risk would be something we'd need to take very seriously.
The way I think of it is that the best defence is a good offence, and that is to say aggressively pursing trade agreements with all countries and with all those who are interested at the multilateral level, which is a difficult process. Having that energy always there and also pursuing bilateral arrangements, which simply adds to the momentum through the back door, is something we're likely to benefit from disproportionately. The bigger the country we're dealing with, the more the benefits favour the smaller country.