Why Trump’s potash threat against Canada isn’t as bizarre as it sounds

U.S. President Donald Trump is trying to lessen Canada's chokehold on potash supply with alternative imports from Belarus — but that's exposing a critical vulnerability in American agriculture. Andrew Chang breaks down why U.S. farmers depend so heavily on Saskatchewan’s vast potash reserves, and why relying on a Russian ally may be easier said than done.(Photo credits: The Canadian Press, Reuters, Adobe Stock and Getty Images)