America's chief adversary on the global stage is no longer Russia. It's China—a country that has experienced astronomical growth in the last few decades, with an economy that's expanded by $12 trillion dollars in the last fifteen years alone. Much of that economic growth is going straight into military spending, with a defense budget that's seen a nearly seven-fold increase over the past twenty years. And yet, its military spending still pales in comparison to that of the United States. But despite all the money that both nations have pumped into fancy new battleships and armored tanks, they also understand that a key paradigm shift in 21st century warfare is already well underway: The decisive battles of the future will largely be fought—and won or lost—in cyberspace. Ian Bremmer explains where the US stands in this competition.

Watch the GZERO World episode: What could spark a US-China war?