The National Post reports in its Thursday edition that Canada has a trade surplus with the United States, in large part because of our oil exports. The Post's Tristin Hopper writes that in July, Canada exported 4.3 million barrels a day, following the expansion of the Trans Mountain pipeline that began operating in May. This has been to Canada's immense benefit as the price differential on this country's crude has narrowed by $10 a barrel compared with last year. However, while Mr. Trump wants to increase production and eliminate the trade deficit, he has also promised Americans "the lowest-cost energy and electricity on Earth." Taxing crude imports from Canada would push up gas prices. Some experts believe oil and gas will be excluded from Mr. Trump's tariffs, as the U.S. looks to Canada as a key supplier of low-cost energy. Canada might even replace out-of-favour suppliers such as Venezuela, which exported 263,000 barrels a day to the U.S. in August. But if Trump did hit Canada with a blanket tariff, prompting Ottawa to retaliate, the ensuing trade war could cause real GDP to fall by 2.4 percentage points over two years and result in a 5-per-cent reduction in export values, according to an analysis by TD Economics.