It takes a long time to stop a demographic supertanker, so China’s population, despite the one-child policy, has still not peaked. When it finally does so in 2025, India’s population will have already exceeded China’s, and may eventually peak at 1.7 billion.
Yet India is only an intermediate-fertility country, not a high-fertility country like Pakistan or Nigeria.
It may surprise that the USA is also an intermediate-fertility country, as defined by the UN. The largest of them, in descending order of population size, are