The government should not reject Trans Mountain, in fact, it should do the opposite.  I'd suggest the government plough ahead with Trans Mountain and put KXL back "under review" until after any negotiation of NAFTA.  Trump made Keystone a campaign issue and therefore withholding it (and the small PR victory) ought to give us some small leverage.  More importantly, this would be a reminder that if NAFTA is ripped up, the proportionality clauses go with it, and Canada will no longer be obligated to send a percentage of its oil and gas production to the US (making KXL much less valuable).  Canada would then be free to sell Oil to Canadians first and reduce the oil imports that NAFTA necessitates.  Withholding Keystone while pushing through projects like Trans Mountain and Energy East signals that we are serious about selling our oil elsewhere - and we're going to need every advantage in the upcoming trade negotiations.