In the hours before Canadian Prime Minister Justin Trudeau announced a 30-day pause on US President Donald Trump’s threatened 25% tariff on Canadian goods, the co-founder of one of Canada’s largest auto parts manufacturers was bewildered.

Canada and Mexico are the top buyers of U.S. exports in more than 72% of all export categories, according to my analysis of the latest U.S. Census Bureau data.

Leaders of the three countries said they agreed to send more troops to the border, tackle U.S. arms smuggling into Mexico and increase collaboration over security issues.