Canada's retaliatory tariffs of up to 50 percent on approximately $19.8 billion worth of US goods came into effect this Tuesday, further escalating the trade war between the two neighbours. Canada's tariffs on hundreds of US products is a calculated risk for Prime Minister Mark Carney. Key points and original sources are listed below.

• Canada's retaliatory tariffs of up to 50 percent on approximately $19.8 billion worth of US goods came into effect this Tuesday, further escalating the trade war between the two neighbours. At the same time, US President Donald Trump is threatening to ban sale...S1

• Canada's tariffs on hundreds of US products is a calculated risk for Prime Minister Mark Carney. US officials have repeatedly said they won’t tolerate retaliation, but declined to specify how or when US President Donald Trump may respond with fresh measures of...S2