Beijing-based high-school teacher Jiang Xueqin may not seem like an obvious candidate for a geopolitical “prophet”. Dressed casually in a polo shirt, the greying Chinese-Canadian looks unassuming. But through his hugely popular Predictive History YouTube channel, Jiang has become known as “China’s Nostradamus”, gaining a following for his outlook on world affairs. While most of his fans are outside China, his lectures and interviews have been translated and uploaded on Chinese social media...