McDonald's is the secret to world peace — or so the economist and New York Times columnist Thomas Friedman famously wrote back in 1999. Friedman’s theory of peace was based on the observation — correct at the time — that no two nations with McDonald's have ever been at war with one another (that is, not since each got their first McDonald's). He was largely correct. It seemed that buying and selling things was humankind's surest path to peace.At least we all thought it was, until 8:59am on 24 February, 2022, when Russian forces began a full-scale invasion of Ukraine...