On Wednesday, Canadian and U.S. negotiators head back to the negotiating table for discussions on overhauling the North American Free Trade Agreement (NAFTA.) Over the weekend, President Trump tweeted that there was no need to keep Canada in the deal and he warned he might terminate it altogether. Then yesterday,  Richard Trumka, the leader of the AFL-CIO labor union, told Fox News he didn’t see how reform of NAFTA could work without Canada. And it’s not just Americans who are divided over the pact. The U.S. and Canada also have some thorny issues to resolve.