It's critical. As Mr. Behboodi mentioned in previous testimony, 75% of our exports go to the United States. Moreover, any unilateral trade measure that Canada puts in place that affects U.S. exports to Canada is going to be met with a typical response from a trade partner that is infamous for its retaliatory capacity.
In plain language, if you put something like this in place without the co-operation of the United States, you screw up an intensely integrated flow of trade in goods back and forth across this border that would have negative implications for both countries.