Premise: A man walks past an electronic stock board showing Japan's Nikkei 225 index and other country's index at a securities firm in Tokyo Monday, Sept. 3, 2018. Asian shares were mostly lower Monday amid worries about escalating trade friction between the U.S. and Canada, who have been unable to agree to a revamped trade deal but will continue negotiating this week. Eugene Hoshiko AP Photo
Hypothesis: The friction between the US and Canada is escalating.