Last year, former Defense Secretary Robert Gates was greeted in Beijing by China's experimental stealth jet buzzing over his head. Gates didn't sweat it: He proclaimed that the J-20 wouldn't be ready until at least 2020. Oops. The Pentagon's top China official has now revised that estimate. The J-20, China's first stealth jet, will be operationally ready "no sooner than 2018," David Helvey, deputy secretary of defense for East Asia and Asia Pacific Security Affairs, told reporters Friday.