USA's tariffs against Canada correct that imbalance and reduce the damage Canada's tariffs cause us. While in a perfect world, low worldwide tariffs would promote the best global economy, the failure of NAFTA and GATT to stop countries' cheating against that principle means the US should take action to restore balance. We can't stop other countries from raising their tariffs against the US, we can only react when they do. For far too long Presidents were unwilling to take action.