It’s been less than a week since the White House confirmed the collapse of the Trans-Pacific Partnership trade deal, and already Asian states are racing to make new trade arrangements without the U.S. This time the focus is on the 16-nation Regional Comprehensive Economic Partnership, or RCEP, a deal that excludes the U.S., goes easy on statist economies and boosts China’s ambition to be the economic and strategic hub of the Asia-Pacific.

Beijing embraced RCEP in 2012 as a counterweight to TPP, but most governments preferred...