The question is what could actually cause the United States to fight China. What if China invades and occupies Taiwan, a democratic U.S. partner and arms customer? Would America actually risk World War III? What if China forces its claim to the Senkaku Islands, which the United States considers to belong to Japan? Does that fall within America’s treaty commitments to defend its ally?

There’s no guarantee that a U.S. president, especially Trump, would resort to war in either case. But these are among the scenarios war-gamers at the Rand Corporation have studied to see if the United States could prevent China from claiming territory by force. It’s not clear that the U.S. could.

Yet the growth of Chinese capabilities represents a big change from about 20 years ago, when President Bill Clinton sent aircraft carriers near the Taiwan Strait to deter Chinese threats against the island. China at the time had been firing missiles toward Taiwan, but its missile arsenal was far less capable and precise. “When that carrier was deployed by President Clinton, the Chinese couldn’t even find it,” Chris Brose, the former staff director for the Senate Armed Services Committee, said at a separate talk at the Aspen forum. “And they’ve spent 25 years not only figuring out how to find systems like that, but how to overwhelm them with very large volumes of precision weapons.”