Will the new Middle East crisis rock the world economy? The markets say no – but I fear they're wrong

Financial markets picked up the clear message when Donald Trump cut short his stay at the G7 summit in the Canadian Rockies this week. Despite calls from fellow western leaders to de-escalate the crisis, the president's early return to the White House was taken as a sign that the US is considering joining Israel in its military action against Iran. Trump says he wants Iran's unconditional surrender. This is where modern summitry came in half a century ago. In 1975, the first meeting of what eventually became the G7 was convened at Rambouillet in France in an attempt to work…