Canada, the United States and Mexico are taking the first step toward negotiating changes to the North American Free Trade Agreement (NAFTA). The trade bloc's talks to renegotiate aspects of NAFTA begin Aug. 16 in Washington, D.C. and will last until Aug. 20. This first round of negotiations will most likely be used to present each side's proposals and demands for updating the agreement. Concrete changes to the trade agreement will not come until several months from now, when the talks are more advanced....