How to “decouple” America and Communist China is the focus of the chairman of the new House committee looking into the threat from the Beijing regime. “Everyone made the same basic bet on China,” Congressman Mike Gallagher says. “But it failed. So now we’re trying to extricate ourselves.” Not everyone made the same bet, we’d cavil. But we wish Mr. Gallagher good luck. We think of it as unfinished business, going back to errors of the 1990s.