Apart from catastrophic events like nuclear war or science-fiction scenarios such as a robot uprising, if there is any single predictable event in the future capable of fundamentally altering the global order, I believe it would be the rise of India.

My reasoning is straightforward: India's sheer size. India is the only country apart from China with a population exceeding one billion, and currently, it has surpassed China as the most populous country, a position it will likely maintain for the foreseeable future.

Therefore, as long as India sustains a reasonable rate of economic growth, it's destined to become one of the top three economies globally. Considering nations like Japan and Germany have populations just a fraction of India's, India doesn't require particularly high per capita GDP levels to economically surpass these countries.