This is from Canadian trade lawyer Lawrence Herman, in a C.D. Howe Institute paper:
Trade remedy cases under Chapter 19 of the NAFTA have been tapering off for several years. There was a flurry of activity under the Free Trade Agreement and in first five years of the NAFTA. However, leaving aside the unique situation of the softwood lumber dispute, there have been only six completed Canadian cases against the US under Chapter 19 since 2000. The last Canadian Chapter 19 challenge was filed in 2006.
With the signing of the Canada-US Softwood Lumber Agreement (SLA) in 2006, settling this longstanding dispute, all remaining Canadian softwood lumber challenges under the NAFTA were terminated. As noted, no other Chapter 19 cases have been initiated by Canadian exporters against US trade agencies since 2006 and only a handful have been brought against Canada by Americans in the last 10 years.
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The decline in trade disputes may be due, in part, to increased integration of the two economies and to the rise of global supply chains, making the Canada-US border – in this sense – less significant to business dealings and less a factor for the application of extraordinary antidumping and countervailing duties. ...