Politicians are always difficult to understand, and the further up the ladder they get the more difficult it becomes - take this article in the Globe & Mail where Martin says we need to develop more aggressive foreign policy, strive for a “peace economy”, and then goes on to talk about economic opportunities in China.
China does present significant opportunities for Canada, China also has significant human rights issues, human rights issues that should be dealt with by the international community that Canada is a part of, and a more aggressive foreign policy should make it perfectly clear that their human rights issues are not acceptable to us as a nation.
— while Martin is (rightfully IMO) talking about the messages being sent by American actions in relation to our softwood lumber dispute he should also be mindful of the messages we send to the world in relation to our dealings with China.

I’m not sure what impact a Canadian cessation of trade would have on China’s Human Rights practices. It seems to me that the best bet is to EXPAND trade. The strategy of economic engagement has created tremendous change over the last two decades. They’ve got a long way to go. But stronger connections to the global economy lead to increasing contact with the West, more travel and exchange between countries, and inevitably a growing demand for democracy within China itself. It’s no accident that when the leadership feels threatened, they cut various channels of communication. The more trade, the less possible that becomes.