U.S. President Donald Trump's increased tariffs on all steel and aluminum imports took effect on Wednesday "with no exceptions or exemptions," escalating the global trade war. Trump's increased tariffs campaign to reorder global trade norms in favor of the U.S. drew swift retaliation. China, the EU, Canada and others have reacted to the with retaliatory tariffs of their own. Canada imposed retaliatory tariffs on 21 billion U.S. goods. We speak with John W. Diamond, Senior Fellow in Public Finance and the senior director of the Center for Public Finance at the Rice University’s Baker Institute.