A professor in Memorial University’s Faculty of Business says Donald Trump’s decision to impose punishing tariffs on his Canadian and Mexican trade partners essentially means any existing trade agreements have been ripped up.

Premier Andrew Furey has called Trump’s action “unlawful” and “illegal.”

Tom Cooper, a professor of strategic management at the Faculty of Business at MUN, says Trump’s executive power allows him to supercede any existing agreements.

Cooper says Trump, like U.S. presidents before him, has the power to “unilaterally decide to do this.” Cooper says “we can take this to dispute resolution and all that, but Trump can say ‘look I don’t care, I’m the President, I’ll do what I want,’ and that’s the danger right now. So these agreements, which Trump negotiated himself back in his first administration, are just being thrown out the window.”