The 21st century kicked off with a more open China, hungry for foreign investment in the heyday of globalization. Things have changed since.

For emerging markets investor Antoine van Agtmael, China has become "much more closed, and [...] developed to have a real sense of itself as a world power." Meanwhile, the US has become more defensive about its global superpower status.

That means we're moving from the American century to the Chinese century, he tells Ian Bremmer on GZERO World.