The Globe and Mail reports in its Saturday edition that three weeks of Donald Trump's war against Iran have hit energy markets and stock markets, and now economists are concerned about economic contagion from the conflict. The Globe's Jason Kirby and Mark Rendell write that the International Energy Agency says the disruption to shipping through the Strait of Hormuz has triggered "the largest supply disruption in the history of the global oil market." Oil prices have fluctuated sharply as traders respond to conflicting statements from the White House and Pentagon. The oil price shock has led to a huge repricing of market expectations for monetary policy. That said, stock markets have taken a big hit, and that has experts concerned. "Oil spikes could transmit faster via equities than the pump, pressuring spending through the wealth effect," wrote Kriti Gupta at JPMorgan. Stock markets are "the transmission mechanism that makes this not just a supply-side issue, but a demand-destructive one." Friday marked the fourth-straight weekly decline for the S&P 500, bringing it to a level it was at last September, and the energy-heavy S&P/TSX composite fell 2 per cent Friday, erasing its gains since the start of the year.