Canada has done the obvious thing by taking the softwood lumber fight to a NAFTA dispute settlement panel. And why not? The Canadian government has gone this route twice before – in 1992 and 2001 – and won both times. Given that track record, last week’s filing under Chapter 19 of the North American free-trade agreement is a no-brainer. There is another, less obvious reason this is an astute move by the Trudeau government. Canada could have held off on a challenge as a sign of goodwill to the Trump administration. Instead, it has given itself a valuable bargaining chip in the ongoing renegotiation of NAFTA. …In short, there is plenty of evidence that the tariffs are inflicting a toll on the U.S. economy. As long as NAFTA lives, Canada should use the tools at its disposal to get what it wants.